I used GoBack years ago when it was still Roxio. Avinash is right; the best it can do is restore your computer to a previous state. If you were infected at that point, all it does is lose all your work since that time - and you're still infected! AS to AV, there are excellent free softwares that I can easily recommend. One is Avira AntiVir Personal Edition. http://www.free-av.com/en/products/1...antivirus.html
Another is Avast! Free Edition http://www.avast.com/en-au/free-antivirus-download and I've been hearing good things about Microsoft Security Essentials, although I haven't tried it myself. http://www.microsoft.com/Security_Essentials/
All three work with Windows 7.
Always code as if the person who ends up maintaining your code is a dangerous psychopath and knows where you live.