Also reinstall any browsers you got. (manually delete any related folders left in profile a and use ccleaner to clean registry before reinstall) For IE roll it back a version by uninstalling the Windows update if you running 7, then reupdate
Well avast found an infected file (it says infected files:1) and the blue circle is now red. LAlsi the percentage (how much it had done i think) just went from about 48% to 16%....
Windows reinstall is always the best option after virus infection, although often not necessary for Windows to function. It's just a matter of whether you can be bothered to reinstall all the software afterwards. I tend to do it every 6 months regardless, a common tactic if you want to keep a pc running at optimum speeds