Hi debra,
Any "unp..." files in that directory are just temp files which avast unpacked in the process of scanning archive files. Normally they get automatically deleted afterwards, but possibly your scan was aborted -- feel free to delete it yourself.
Maybe it's not necessary, but I've gotten into the habit of pausing avast's Standard shield while running defrag, Maybe there's no conflicts, but if nothing else it might help the defrag run a little faster and smoother. Don't forget to Resume it afterwards, of course.
Unrelated to avast, if you happen to also have Javacool's SpywareGuard, it's recommended that you disable its protections (save new settings that way) and then exit the program before defragging because of reported conflicts with defrag. Don't forget to restart it and set the protections active again (and save settings again) afterwards.
Hopefully this will help clear up your problems.
Best,
Mike