I have identified the file that prevent me from further shrinking C: partition for Windows 7 OS.
By query shrinking and then checking Event Viewer, this is the file:
The last unmovable file appears to be: \ProgramData\Microsoft\Search\Data\Applications\Wi ndows\Projects\SystemIndex\Indexer\CiFiles\0001001 5.wid::$DATA
I was wondering how to move this file away? I guess I have to move the whole \ProgramData away, not just that file?