Not indexed file attribute can be set to specify that file or folder must not be indexed by Windows Indexing Service. Windows Indexing Service creates an index of document content and properties and stores it in catalogs in order to optimize system for faster file searching. Indexing attribute if applied to folder covers also all folder content including all of its subfolders.
Indexing Service runs automatically and stops only when everything is indexed or disk space is running low. Not indexed attribute is automatically set to corrupted or inaccessible files in order not to skip them in further indexing process.
With Febooti fileTweak it is possible to set Not indexed attribute in order to specify files or folders that are no to be indexed.