Windows 10 users experience, PC Laptop Freezes continuously, Not responding to clicks at startup. And checking on Taskmanager There is a process named Microsoft windows search indexer chewing up the massive amount of RAM or CPU. Its almost 100% CPU or Memory usage by SearchIndexer.exe. Here this post we discuss What is SearchIndexer.exe and How to fix Microsoft windows search indexer high CPU usage on windows 10.
Post Contents :-
- 2 Fix windows 10 search indexer high CPU usage
What Is SearchIndexer.exe?
Searchindexer.exe is built-in Windows service that handles indexing of your documents, files, folder etc for the Windows Search. It basically powers the Windows file search engine which helps in functioning of Windows features like the Start Menu search, File Explorer search etc.
And Microsoft windows search indexer high CPU usage, Mostly occur if you have recently rebuild the search index, or accidentally deleted the index data folder. Again sometimes corrupted system files, Virus malware infection also causes this problem. Whatever the reason, Here some solutions you may apply to reduce CPU usage, fix Microsoft windows search indexer high CPU usage windows 10.
Fix windows 10 search indexer high CPU usage
Frist perform a full system scan for Virus malware infection with a latest updated Antivirus Application. And Run System optimizer like Ccleaner to clean up system junk, cache, memory dump files etc. Also run the registry cleaner to clean up and fix broken registry errors.
Open the command prompt as administrator, type sfc /scannow and hit the enter key to run the sfc utility which scans for missing corrupted system files, If found any the system file checker will restore them itself form a compressed folder located on %WinDir%System32dllcache. After 100% complete the scanning process Restart windows and check CPU, memory usage came to the normal state
Restart Windows Search Service
Press Windows Key + R, type services.msc and hit Enter to open windows services. Here scroll down and double click on windows search service to get its properties. Check the service its running or not. If not running simply start the service and change its startup type automatic.
If the service is running state then, Change startup type disable and Stop the service, click apply ok to make save changes. Restart Windows, and again open Open windows search properties from windows services. This time change the startup type automatic ( delayed start ) and start the service next to service status. Click apply and ok to make save changes, And check CPU Usage consumed by searchindexer.exe has dropped.
Run Search and Indexing Troubleshooter
Run the Build in search and indexing troubleshooter and let windows to check and fix the problem itself. If you are windows 10 user simply type troubleshoot in start menu search and hit the enter key. Then scroll down, Select search and indexing and run the troubleshooter.
Or windows 8.1 and 7 users open Control panel -> Troubleshooting -> View all -> run the Troubleshooter for Search and Indexing.
When ask what problems do you notice, select Files don’t appear in search results and then click Next. and let windows to check and fix if search and indexing causing any problem which result High CPU usage, or 100% memory usage.
Reduce the Amount of Indexed Data
This is another best way to fix High CPU usage by searchindexer.exe. Simply Reducing the amount of data the Search Indexer is indexing by steps following steps below.
Type Indexing options on start menu search and hit the enter key. And click on Modify button to open the Indexed Locations window.
Then Click the arrow beside the C: drive to expand its folders. Now you can deselect some of the checkboxes to remove indexed locations. Press the OKbutton on the Indexed Locations window. Click Close on the Indexing Options window.
Rebuild Windows Search Indexer
If reducing the indexed locations doesn’t greatly cut the Search Indexer’s CPU utilization, you can also select to rebuild the index. Rebuilding the index can resolve numerous Windows Search issues, And this can seriously improve the performance of your Start Menu search box as well.
To do this again open windows indexing options, click modify and deselect all the selected locations except the OS C: drive as shown below. Then click ok to go back to indexing options window.
Then go to Advanced indexing options and click Rebuild index button. Now you will see this message: Rebuilding the index might take a long time to complete. Some view and search results might be incomplete until rebuilding is finished. Press the OK button to confirm and rebuild the index.
What it does is at the top of the Indexing options window your indexing will go from whatever number it is to zero and it’s going to start building index again.
Disable the Search Indexer Service/feature
If all above methods fail to fix windows 10 search indexer high CPU usage, Then simply disable This service from windows services and Turn off windows search Feature form windows features.
To do this open windows services by press windows + R, type services.msc and hit the enter key. Then scroll down and double click on windows search. Here on Windows search properties change the startup type disable and stop the service next to running status.
Type windows features on start menu search and hit the enter key. Here on windows features, Scroll down and look for Windows Search. When you got it simply Deselect the windows search checkbox and ok to make save changes. Restart your PC and check there is no more searchindexer.exe running on task manager or CPU, Disk And memory usage came to the normal state.
These are some most applicable solutions to fix windows 10 search indexer high CPU usage, or 100% disk usage problem. And I am sure one of these solutions will fix the issue for you. Still, have any query, a suggestion about this post feel free to discuss on comments below Also Read Antimalware service executable High CPU Disk usage windows 10.
-->Filter handlers, which are implementations of the IFilter interface, scan documents for text and properties. Filter handlers extract chunks of text from these items, filtering out embedded formatting and retaining information about the position of the text. They also extract chunks of values, which are document properties. IFilter is the foundation for building higher-level applications such as document indexers and application-independent viewers.
This topic is organized as follows:
- About the IFilter Interface
- Finding the IFilter Class Identifier
About the IFilter Interface
Microsoft Windows Search uses filters to extract the content of items for inclusion in a full-text index. You can extend Windows Search to index new or proprietary file types by writing filters to extract the content, and property handlers to extract the properties of files.
The IFilter interface is designed to meet the specific needs of full-text search engines. Full-text search engines like Windows Search call the IFilter methods to extract text and property information and add them to an index. Windows Search breaks the results of the returned IFilter::GetText method into words, normalizes them, and saves them in an index. If available, the search engine uses the language code identifier (LCID) of a text chunk to perform language-specific word breaking and normalization.
Windows Search uses three functions, described in the following table, to access registered filter handlers (implementations of the IFilter interface). These functions are especially useful when loading and binding to an embedded object's filter handler.
Function | Description |
---|---|
LoadIFilter | Gets a pointer to the IFilter that is most suitable for the specified content type. |
BindIFilterFromStorage | Gets a pointer to the IFilter that is most suitable for the content contained in an IStorage Interface object. |
BindIFilterFromStream | Gets a pointer to the IFilter that is most suitable for a specified class identifier (CLSID) retrieved from a stream variable. |
The IFilter interface has five methods, described in the following table.
Method | Description |
---|---|
IFilter::Init | Initializes a filtering session. |
IFilter::GetChunk | Positions IFilter at the beginning of the first or next chunk and returns a descriptor. |
IFilter::GetText | Retrieves text from the current chunk. |
IFilter::GetValue | Retrieves values from the current chunk. |
IFilter::BindRegion | Retrieves an interface representing the specified portion of object. Reserved for future use. |
Isolation Process
Windows Search runs IFilters in the Local System security context with restricted rights. In this IFilter host isolation process, a number of rights are removed:
- Restricted Code
- Everyone
- Local
- Interactive
- Authenticated Users
- Built-in Users
- Users' security identifier (SID)
The removal of these rights means the IFilter interface does not have access to the disk system or network or to any user interface or clipboard functions. Furthermore, the isolation process runs under a job object that prevents child processes from being created and imposes a 100 MB limit on the working set. the IFilter interface host isolation process increases the stability of the indexing platform, due to the possibility of incorrectly implemented third-party filters.
Note
Filter handlers must be written to manage buffers, and stack correctly. All string copies must have explicit checks to guard against buffer overruns. You should always verify the allocated size of the buffer. You should always test the size of the data against the size of the buffer.
IFilter DLLs
IFilter DLLs implement the IFilter interface to enable a client to extract text and property value information from a file type, class, or perceived type. The Windows Search filtering process SearchFilterHost.exe binds to the IFilter that is registered for the class, perceived type, or name extension of the item.
IFilter Structure
Each IFilter is a DLL file that implements an in-process Component Object Model (COM) server to supply the specified filtering capabilities. The following figure illustrates shows the overall structure of a typical IFilter DLLs. A more complex example could implement more than one IFilter class.
Native Code
Filters must be written in native code due to potential common language runtime (CLR) versioning issues with the process that multiple add-ins run in. In Windows 7 and later and later, filters written in managed code are explicitly blocked.
Finding the IFilter Class Identifier
The class of the IFilter DLL is registered under the PersistentHandler registry key. The following example, for HTML files, illustrates how to find the IFilter DLL for an HTML document. This example follows logic similar to that used by the system to find the IFilter associated with an item.
- Check whether the extension for the type of files that the DLL filters has a PersistentHandler registered under the registry entry HKEY_LOCAL_MACHINESOFTWAREClasses. Let this key be
Value1
. If that entry already exists, then skip to step 4 of this procedure and useValue1
in that key. The values are of type REG_SZ.
- Alternatively, if there is not a PersistentHandler registered for the extension, find the CLSID associated with the document type under the registry entry HKEY_LOCAL_MACHINESOFTWAREClasses. Let this key be
Value2
.
- Determine whether a PersistentHandler is registered for the CLSID. Using
Value2
determined in step 2, find the PersistentHandler for the HKEY_LOCAL_MACHINESOFTWAREClassesCLSIDValue2 entry. Let this key beValue3
.
- Determine the IFilter persistent handler GUID. Using
Value1
andValue3
, find the IFilter Persistent Handler GUID for the document type. The value under the registry entry HKEY_LOCAL_MACHINESOFTWAREClassesCLSIDValue1 or 3PersistentAddinsRegistered 89BCB740-6119-101A-BCB7-00DD010655AF'/> yields the IFilter PersistentHandler GUID for this document type. Let this key beValue4
. In this example, the IFilter interface GUID is 89BCB740-6119-101A-BCB7-00DD010655AF.
Note
In this example, the IFilter DLL for HTML documents is nlhtml.dll.
IFilter::GetChunk and Locale Code Identifiers
The LCID of text can change within a single file. For example, the text of an instruction manual might alternate between English (en-us) and Spanish (es) or the text may include a single word in a language other than the primary language. In either case, your IFilter must begin a new chunk each time the LCID changes. Because the LCID is used to choose an appropriate word breaker, it is very important that you correctly identify it. If the IFilter cannot determine the locale of the text, then it should return an LCID of zero with the chunk. Returning an LCID of zero causes Windows Search to use Language Auto-Detection (LAD) technology to determine the locale ID of the chunk. If Windows Search cannot find a match, it defaults to the system default locale (by calling the GetSystemDefaultLocaleName Function function). For more information, see IFilter::GetChunk, CHUNK_BREAKTYPE, CHUNKSTATE, and STAT_CHUNK.
If you control the file format and it currently does not contain locale information, you should add a user feature to enable proper locale identification. Using a mismatched word breaker can result in a poor query experience for the user. For more information, see IWordBreaker.
Note
Filters are associated with file types, as denoted by file name extensions, MIME types or CLSIDs. While one filter can handle multiple file types, each type works with only one filter.
Additional Resources
- The IFilterSample code sample, available on GitHub, demonstrates how to create an IFilter base class for implementing the IFilter interface.
- For an overview of the indexing process, see The Indexing Process.
- For an overview of file types, see File Types.
- To query file association attributes for a file type, see PerceivedTypes, SystemFileAssociations, and Application Registration.
Related topics
Compatible with Windows 10, 8, 7, Vista, XP and 2000
Optional Offer for WinThruster by Solvusoft | EULA | Privacy Policy | Terms | Uninstall
Overview of SearchFilterHost.exe
What Is SearchFilterHost.exe?
SearchFilterHost.exe is a type of EXE file associated with Windows 10 Operating System developed by Microsoft Corporation for the Windows Operating System. The latest known version of SearchFilterHost.exe is 7.0.10240.16384, which was produced for Windows. This EXE file carries a popularity rating of 1 stars and a security rating of 'UNKNOWN'.
What Are EXE Files?
EXE ('executable') files, such as SearchFilterHost.exe, are files that contain step-by-step instructions that a computer follows to carry out a function. When you 'double-click' an EXE file, your computer automatically executes these instructions designed by a software developer (eg. Microsoft Corporation) to run a program (eg. Windows 10 Operating System) on your PC.
Every software application on your PC uses an executable file - your web browser, word processor, spreadsheet program, etc. - making it one of the most useful kinds of files in the Windows operating system. Without executable files like SearchFilterHost.exe, you wouldn't be able to use any programs on your PC.
Why Do I Have EXE Errors?
Because of their usefulness and ubiquity, EXE files are commonly used as a method of delivery for virus / malware infection. Often, viruses will be disguised as a benign EXE file (such as SearchFilterHost.exe) and distributed through SPAM email or malicious websites, which can then infect your computer when executed (eg. when you double-click the EXE file).
In addition, viruses can infect, replace, or corrupt existing EXE files, which can then lead to error messages when Windows 10 Operating System or related programs are executed. Thus, any executable files that you download to your PC should be scanned for viruses before opening - even if you think it is from a reputable source.
When Do EXE Errors Occur?
EXE errors, such as those associated with SearchFilterHost.exe, most often occur during computer startup, program startup, or while trying to use a specific function in your program (eg. printing).
Common SearchFilterHost.exe Error Messages
The most common SearchFilterHost.exe errors that can appear on a Windows-based computer are:
- 'SearchFilterHost.exe Application Error.'
- 'SearchFilterHost.exe is not a valid Win32 application.'
- 'SearchFilterHost.exe has encountered a problem and needs to close. We are sorry for the inconvenience.'
- 'Cannot find SearchFilterHost.exe.'
- 'SearchFilterHost.exe not found.'
- 'Error starting program: SearchFilterHost.exe.'
- 'SearchFilterHost.exe is not running.'
- 'SearchFilterHost.exe failed.'
- 'Faulting Application Path: SearchFilterHost.exe.'
These EXE error messages can appear during program installation, while a SearchFilterHost.exe-related software program (eg. Windows 10 Operating System) is running, during Windows startup or shutdown, or even during the installation of the Windows operating system. Keeping track of when and where your SearchFilterHost.exe error occurs is a critical piece of information in troubleshooting the problem.
-->This topic describes the three stages of the indexing process and the primary components involved in each, explains the timing of indexing activity, and provides some notes for third-party developers who want their data stores or file formats indexed.
This topic is organized as follows:
Overview
Windows Search supports the indexing of properties and content from files of different file formats, such as .doc or .jpeg formats, and data stores, such as the file system or Windows Outlook mailboxes. Photo fx lab crack key. There are two kinds of indices: value indices that allow filtering and sorting by the whole value of a property and inverted indices that index words within textual properties or content. If you have a custom file format or data store, you need to understand how Windows Search indexes in order to get your items indexed correctly.
The indexing process happens in three stages controlled by a Windows Search component called the gatherer. In the first stage, the gatherer adds URLs to queues. The URLs identify items to be indexed, and the queues are merely prioritized lists of URLs. In the second stage, the gatherer coordinates other Windows Search and third-party components to access the items and collect data about them. Finally, in the third stage, the data collected is added to the index.
The following diagram shows the principal components and flow of data through the indexing process. A number of components are involved in collecting data for the index. Some of these are a part of Windows Search, and some come from third-party applications. If you have a custom data store or file format, Windows Search relies on your protocol handler and filter for accessing URLs and emitting properties for indexing. Windows Search components are shown in blue, and third-party components are shown in green.
Stage 1: Queuing URLs for Indexing
In the first stage of indexing, the gatherer collects information about updates to data stores, compares that information to the known crawl scope, and then builds a queue of URLs to traverse to collect data for the index. For sources that are not based on notification, such as FAT drives, the gatherer periodically initiates a full traversal of the crawl scope so that the data in the index is kept fresh. For sources such as NTFS, there is only a single crawl and everything else is handled by notifications from the USN Change Journal. There is also no crawl of Microsoft Outlook. The following diagram shows a high-level view of the queuing process for non-crawl indexing.
The rest of this section explains how Windows Search determines what URLs to crawl, and defines some important terms along the way.
Crawl Scope The crawl scope is a set of URLs that Windows Search traverses to collect data about items that the user wants indexed for faster searches. Windows Search adds some URLs to the crawl scope by default, like paths to users' Documents and Pictures folders. Other URLs can be added by third-party applications, users, and Group Policy. Finally, both users and Group Policy can explicitly exclude URLs. Windows Search takes all the added URLs and removes the excluded URLs to determine the crawl scope. This is the working set of URLs from which the gatherer begins its work.
Gatherer The gatherer is a Windows Search component that collects information about URLs within the crawl scope and creates a queue of URLs for the indexer to crawl. When an item in the crawl scope is added, deleted, or updated, the gatherer is notified by the data store's notifications provider. There is an initial crawl where the gatherer starts at the crawl scope root. The URL is passed to the protocol handler and then to the appropriate IFilter. The filter is usually a directory enumeration that produces more URLs. Notifications are the steady-state. Typically, each data store has its own protocol handler that provides these notifications. For example, on the local file system, the USN Change Journal acts as a notifications provider for all URLs under the file:// protocol. Similarly, Microsoft Outlook acts as a notifications provider for all URLs under the mapi:// protocol. When a user receives, moves, or deletes email, Outlook notifies the gatherer of the changed status of the email. From these notifications, the gatherer creates indexing queues of URLs to crawl.
Indexing Queues The indexing queues are lists of URLs that identify items that need to be indexed or re-indexed. The gatherer compares the URLs it receives from notifications providers to the URLs in the crawl scope. Every URL from notifications providers that falls within the crawl scope is added to a queue that the gatherer uses to prioritize which URLs to process next.
There are three queues: high priority notifications, normal notifications, and periodic crawls. The high priority queue is for notifications that should be processed immediately. For example, when a user changes an item's title property in Windows Explorer, the Windows Explorer view needs to be updated immediately after the change. The normal notification queue is for all remaining change notifications. The notification queues are processed before the crawl queue because changed items are more likely to be of interest to a user. The gatherer accesses data for the URLs on each queue in first in, first out (FIFO) order.
For more information on prioritization, and eventing APIs introduced in Windows 7, see Indexing Prioritization and Rowset Events in Windows 7. For more information on crawl scope management and notifications, see Providing Change Notifications and Using the Crawl Scope Manager.
Stage 2: Crawling URLs
In the second stage of indexing, the gatherer crawls through the queues, accessing data stores and retrieving item streams. First, the gatherer finds the appropriate protocol handler for each URL. Then, the gatherer passes the URL to the protocol handler. The protocol handler accesses the item and passes item metadata back to the gatherer. The gatherer uses the metadata to identify the correct filter.
The following diagram shows a high-level view of the URL-crawling process. This stage includes considerable coordination and communication between components.
The rest of this section describes how Windows Search accesses items for indexing and explains the roles of each of the components involved.
Gatherer In stage 2, the crawling stage, the gatherer processes the URLs in the queues, beginning with the high priority queue. Each URL is examined to identify its protocol. The gatherer then looks up the protocol handler registered for that protocol and instantiates it in the search protocol host process.
Search Protocol Host The search protocol host is merely a boxed, host process for protocol handlers. Typically, Windows Search creates two such host processes, one that runs in the system security context and one that runs in the user security context. This separation ensures that data specific to a user is never run in the system context.
Windows Search also uses the host process to isolate an instance of a protocol handler from other processes or applications. This way, no outside application can access that specific instance of the protocol handler, and if the protocol handler fails unexpectedly, only the indexing process is affected. Because the host process runs third party code (protocol handlers), Windows Search periodically recycles the process to minimize the time a successful attack has to exploit information in the process. Beyond this, the search protocol host does not affect the crawling of URLs or indexing of items.
Protocol Handlers Protocol handlers provide access to items in a data store using the data store's protocol. For example, the NTFS protocol handler provides access to files on a local drive using the file:// protocol. The protocol handler knows how to traverse the data store, identify new or updated items, and notify the gatherer. Then, when crawling begins, the protocol handler provides an IUrlAccessor object to the gatherer to bind to the item's underlying stream and return item metadata such as security restrictions and last modified time.
Note
Searchfilterhost.exe
Protocol handlers are not Windows Search components; they are components of the specific protocol and data store they are designed to access. If you have a custom data store you want indexed, you need to implement a protocol handler. For more information on protocol handlers and how to implement one, refer to Developing Protocol Handlers.
Metadata and Stream Using metadata returned by the protocol handler's IUrlAccessor object, the gatherer identifies the correct filter for the URL. The gatherer parses the item's file name extension and looks up the filter registered for that extension. If the gatherer is unable to find a filter, Windows Search uses the metadata to derive a minimal set of system property information (like System.ItemName) and updates the index. Otherwise, if the gatherer finds the filter, the third stage of indexing begins.
Stage 3: Updating the Index
In the third stage of indexing, the gatherer instantiates the correct filter for the URL and initializes the filter with the stream from the IUrlAccessor object. The filter then accesses the item and returns content for the index. If you have a custom file format, Windows Search relies on your filter to access URLs and emit content and properties for indexing.
The following diagram shows a high-level view of the data access process. This stage includes considerable coordination and communication between components.
The rest of this section describes how Windows Search accesses item data for indexing and explains the roles of each of the components involved.
Gatherer At the beginning of this stage, the gatherer's role is to instantiate the correct filter for the item and pass it the item stream. At the end of this stage, the gatherer takes the content and properties emitted by the filter and property handler and updates the index.
Filter Host The filter host is merely a host process for filters and property handlers and serves a purpose similar to the search protocol host. The host process isolates filters and property handlers from the rest of the system for the same security and stability reasons that search protocol host processes isolate protocol handlers. The host process runs with minimal rights (it can't even access the file system) and is occasionally recycled to protect against security attacks. Windows Search also monitors resource use so that if a filter consumes too many resources, the host process is recycled.
Filters Filters are critical components in the indexing process that emit item information for the gatherer. Filters are named after the principal interface used in their implementation, the IFilter interface, and consequently are sometimes referred to as IFilters. There are two kinds of filters: one that interacts with individual items like files and one that interacts with containers like folders. Both provide data for the index.
Using metadata returned by the protocol handler's IUrlAccessor object, the gatherer identifies the correct filter for a particular URL and passes it to the stream. The gatherer identifies the correct filter either through a protocol handler or by the file name extension, MIME type, or class identifier (CLSID). If the URL points to a container, the filter emits properties for the container and enumerates the items in the container (child URLs). If the URL points to an item, the filter returns the textual content, if any the reading of properties and are more complex than property handlers. Generally, we recommend that filters emit item contents while property handlers emit item properties. However, if your filter needs to work with older applications that do not recognize property handlers, you can implement the filter to emit properties as well.
Note
Filters are not Windows Search components; they are components related to the specific file format or container they are designed to access. For more information on filters and how to implement one for a custom file format or container, see Best Practices for Creating Filter Handlers in Windows Search.
The following table lists the results that the gatherer receives from a filter (IFilter) and property handler (IPropertyStore) during the indexing process.
IFilter | IPropertyStore | |
---|---|---|
Allow write | No | Yes |
Mix content and properties | Yes | No |
Multilingual | Yes | No |
Emit links | Yes | No |
MIME | Yes | No |
Text boundaries | Sentence, paragraph, chapter | None |
Client / server | Both | Client |
Implementation | Complex | Simple |
Property Handlers Property handlers are components that read and write properties for a particular file format. They access items and emit properties for the gatherer in the same way that filters do for content. Property handlers are easier to implement than filters. If a text-based file format is very simple or the files are expected to be very small, the property handler can emit both properties and content.
Note
Property handlers are not Windows Search components; they are components related to the specific file format they are designed to access. For more information on property handlers and how to implement one for a custom file format, see Developing Property Handlers for Windows Search.
Properties Windows Search provides a property system that includes a large library of properties. Any property can appear on any item as defined by the filter or property handler. If you have a custom file format, you can map your file format's properties to these system properties, and you can create new custom properties. When your filter or property handler emits these properties, the gatherer updates the index so users can search using your properties. For more information on creating and registering custom properties for a file format, see Property System.
SystemIndex The index, called SystemIndex, stores indexed data and is composed of a property store and indices over the properties and content for item properties, and an inverted index for textual content and properties. After the gatherer updates the index, the index can be queried by Windows Search and other applications. For more information on ways to query the index, see Querying the Index Programmatically.
Note
Remember that when you re-register a schema, changes made to attributes of previously defined properties may not be respected by the indexer. The solution is either to rebuild the index, or introduce new properties that reflect the changes instead of updating old ones (not recommended). For more information, see Note to Implementers in Properties System Overview.
How Indexing is Scheduled
When Windows Search is first installed, it performs a full indexing of the crawl scope, pausing during periods of high I/O and user activity. The default crawl scope consists of the default library locations, such as Documents, Music, Pictures, and Videos. Notifications are processed even before the initial crawl is finished. Occasionally, the gatherer crawls the URLs from the full crawl scope. These full crawls ensure that the data in the index is fresh. For example, if a notification provider fails to send notifications or if the Windows Search service is terminated unexpectedly, the gatherer would have no knowledge of new or changed items and would not index these items. There are two kinds of sources: notification only and notification enabled. In both sources, the gatherer initially crawls the index. After the initial crawl, the notification-only sources will never do a full crawl again unless there is a failure, such as the USN Change Journal rolling over. Notification-enabled sources do an incremental crawl when the indexer is started, but then listen to notifications while running. NTFS and Microsoft Outlook are notification only. Internet Explorer and FAT are notification enabled.
Notes to Implementers
The quality of the data in the index and the efficiency of the indexing process depend largely on your filter and property handler implementation. Because the filter is called every time a URL identifies your file format, the indexing process can slow down dramatically if your filter is inefficient. If your property handler doesn't correctly map all file properties to system properties or doesn't correctly emit these properties, the data in the index will be incorrect and later searches for those properties will return incorrect results. If your filter or property handler fails, the indexer won't be able to index data.
Applications and processes other than Windows Search rely on protocol handlers, filters, and property handlers. Your implementations can affect those applications in ways you may not expect. The Windows Search Development Guide provides advice on design choices and on testing each of these components.