Note Indexing Service is no longer supported as of Windows XP and is unavailable for use as of Windows 8. Instead, use Windows Search for client side search and Microsoft Search Server Express for server side search.
The UsnReadMinSize entry is the minimum size that the USN journal must attain before processing of change notifications can proceed.
|Range:||1 - 524288|
The processing of change notifications proceeds when either the size of the USN journal reaches the value of the UsnReadMinSize entry or an interval of time equal to the value of the UsnReadTimeout entry has passed (and there are entries in the USN journal).
Build date: 9/10/2012