I'm pretty sure that script above is what you're looking for art, although it MAY not be. IIRC, the reason it's difficult to delete large avis - and what that reg fix is for - is because XP tries to get the full info for the file before "releasing it" so, with a 700 MB avi for example, it scans the full 700 MB before it "releases" it. Even without the fix it is possible to delete the avis without a restart or anything though. If you're not using the classic folder view, click on the avi and just wait for the thumbnail to pop up in the details section on the left of the window. When the thumbnail of the video pops up, it's ready to be deleted 90% of the time. Nonetheless, it makes it much less of a hassle
I suspect the same is the reason for your customer's issues (although I'm not positive). Either way, the fix is good to run anyways, even if it doesn't fix your customer's problem...but I think it will.