I've found this to be a problem for months now, though only about 30% of the time; sometimes files downloaded in Chrome will be in some way suspended, and Explorer can't move or rename them (it just hangs indefinitely on the copy dialog or hangs when I try to rename them). Killing all Chrome-related processes makes no difference. Killing and restarting explorer makes no difference. This is occurring across multiple Chrome versions and on many, many new customer machines with both OEM and our own fresh installations of Windows 7 and 8. It happens regardless of User Account Control status. Thoughts?
I sometimes come across this, but not necessarily just with Chrome downloads, but also after copying/moving files. What I do is select a file, cut it and then paste it back to its starting/existing location. Which then seems to free up the new/moved/copied files... I've always assumed it was something to do with a flag within windows file explorer somehow recognising that they're in use not being reset correctly...
Have you tried using Unlocker? Used to be a lifesaver when I ran Windows, that. Just right-click on the file, choose 'Unlock,' then delete.
+1 with the av. I had that kind of problem on a machine running avg. Took that off problem went, so then installed avira. Cleared up. Was few years ago mind you on family member PC.