Don't worry about the Smitfraudfix - that won't run on 64-bit, but I included it just in case. It does some useful work on older versions of windows
I suggest you remove the free AVG and instead install the free version of Avast
Update it, and then scan the whole machine
avast! | Download Free Antivirus Software or Internet Security
Note that you have to register the Avast program every 11 months, but you don't need to use a real e-mail address. Anything will do (
[email protected] works)