Avira has a pretty good free antivirus program to replace AVG. I use that and malwarebytes (I paid for the premium version, but the free version is great also), and spybot. I also run CCleaner and CleanUp! about once a week or so.
If I recall correctly, AVG is a bitch to uninstall, I think that you have to D/L and run a removal program from the AVG website in order to do it correctly.