I use the NirSoft OpenedFilesView utilty to tell me which program has a file open. It works most of the time.
Also, I often find that I cannot unmount a flash drive or USB hard drive, and if I actually kill the explorer process (with Task Manager) then restart it (with File | New Task | explorer) then I can unmount the USB device. Yes, it's a little scary, since killing the explorer process will cause the desktop icons and taskbar to all disappear, which is why you can only restart it with Task Manager. (The New Task menu choice may only appear if you are in the Processes tab.) But it works for me almost every time, and only takes a few seconds.
Terribly flawed, yes, but what do you want from Microsoft? And in fairness, it is a 10-year-old OS.
What's interesting to me is that I have trouble unmounting a USB HDD I've used for backup in W7 (W7 won't let it go, claiming it's still in use), yet old, grey-haired XP releases it instantly on other machines. Go figure!
Originally Posted by Jeffiekins
I know this is an old thread, but Im hoping you are possible still around. Did you ever find a resolution?
I am having this same problem running Win 7 pro 64 bit.
Originally Posted by BKB
Unfortunately, I never did find any method which would work, so I eventually gave up. Naturally, once I gave up, the problem went away at some point, as I haven't been plagued with it in a long time.
Sorry I can't give you some magic answer which will help you solve this problem, but if you ever do solve it, by all means please post it here. There are a lot of us who would be very interested to know the solution.