IFilters are plugins that allow the Windows Indexing Service and the newer Windows Desktop Search to index different various file formats so that they become searchable. Without an appropriate IFilter, contents of a file cannot be indexed.

External links

• Filter Central — Microsoft Search Filters Discussion Board;
• IFilter at MSDN — Interface documentation on MSDN;
• IFilter.org — Downloads and documentation;
• MSG IFilter — IFilter for Outlook Message Files (.MSG) for Windows Desktop Search;
• IFilterShop — Some IFilters available as free for non-commercial users.

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