Windows 7 thumbnails not displaying after malware?

I was on the internet and got a pop up and some thing running in the background and now thumbnails are displaying really slow and some cases not displaying at all.

I ran Malwarebyte and Microsoft security essentials and it found nothing. I deleted the history, temp folder, ran TFC program and restarted the computer. And still having problems with thumbnails.

I had similar problem in past where thumbnails where displaying really slow after I got malware and ComboFix well it fixed the problem.

But because I have not back up the computer, I’m not sure if I should run ComboFix or mess around with other malware remover tools.

The strange thing is my other user profile on the computer is not having this problem.

I would like to back up the computer before I start messing around with remover tools but the thumbnails are not displaying. ( I can still watch videos, listen to music, look at pictures and show documents) It just not showing the thumbnails. So you have to click on each file to see what it is.

But my other user profile on the computer is not having this problem.

It seems I still may have malware on the computer and some how it computerized that user account. The other user profile accounts don’t seem to have that problem displaying thumbnails.

So my question is what kind of malware could cause problems with thumbnails? And how should I back up the computer before running ComboFix or other malware remover tools?

Do you mean Desktop Icons ?
Personally I would just create a new account, transfer any personal stuff and delete that one.