Since you say the problem started right after you reinstalled I personally would try reinstalling again. Sounds like something didn't go right. It's quite possible the drivers, etc that you have now are not the ones the internet seller used. Is the copy of W7 that you installed the one that came with the computer or where did you get it? I would suggest you download the latest
W7 SP1 ISO from Microsoft and install that.
Other ideas, you said you installed AVG after it started so it's possible you have a virus. You could try downloading RKILL (RKILL has several filenames of basically the same thing so if one doesn't work try another) and then without rebooting after RKILL runs, run the freeware edition of Malwarebytes (select NO to the free trial because you should not have two active anti-virus programs running). Find links to RKILL and Malwarebytes in our
Freeware DB.
Quite honestly freezing problems can be caused by so many things that it is often trial and error.
BTW: a driver within Daemon Tools can cause BSODs but you aren't getting BSODs so could that be an issue, I don't know but hunch says no. Personally I have never had an issue with it on my computer but if you do get a BSOD the experts will recommend deleting it.