That’s because AVG is terrible.
Run a Spybot and Malwarebytes scan then run the Onecare Safety Scanner.
If those come up clean you can run an Avira scan just to be on the safe side but I imagine the other 3 will have caught anything.
For Windows7 you need MSDN/MSDNAA. I also take cash.
You may not have a virus but to jump around in HD space like that is definately not normal for windows. Some viruses will use your computer as a storage dump for warez. I imagine that’s more likely than temp files.