Prevent indexing certain paths

If you enable this policy setting, you specify a list of paths to exclude from indexing. The user cannot enter any path that starts with one of the paths you specified. On a per-user basis, this policy setting will work only if a protocol handler referencing a SID-based user scope, such as MAPI, is specified. File system paths that do not reference a specific SID will not be excluded from indexing if these are only specified in the Group Policy under "User Configuration." To restrict a file system path from indexing, please specify the file system path to be indexed under the "Computer Configuration" Group Policy.

If you enable and then disable this policy setting, users can index any path not restricted by other policies, but their original list of paths to index is not restored.