>>69
Never encountered such an issue (unsolvable without reboot). Open file handles are freed once the process is terminated ( an exception to this is when you have a process which is being debugged, and while it has been terminated, its handles and memory space aren't freed until you have the debugger close the process ). There was a case when explorer didn't close the handle to some video files which have been previewed ( preview is handled by multiple third party directshow filters, such as haali's splitter/ffdshow video decoder, but this happens within explorer's process), restarting explorer would close those handles.