Didn't know whee else to put this, but I had a hell of a time trying to get rid of a large ISO file from my Win7 X64 system. FileUnlocker is a freeware I used to use but it doesn't work on X64 systems. LockHunter is another - it works on X64, but it couldn't unlock this file because it said a system process was locking it. I also tried ending explorer.exe and deleting through a command prompt, but that didn't work.
SO: I tried Kevin's Delete Doctor, and its setting to delete on restart did the trick, no need to open a recovery console and hunt for the thing manually. I recommend this as a useful little tool to have around like his Clean Disk Security. Thanks, Kevin!
(Note: the Delete Doctor download is an executable - no install required. Make sure when you download it to select the "save" option, not the "run" option you might choose if this were a setup file.)
Edited to add the link