How do I get rid of a virus on google? And what can this virus do?

I keep being redirected when I click on google links after I search something (it's only google links I have problems with). I've never had virus problems before and even with this one my computer runs completely fine and is as fast as it was before. I have the free Avira AntiVir, Windows Defender, and Spyware Blaster and made scans and some viruses were detected and dealt with but I still had the same problem. What should I do to get rid of the virus? Also, I was wondering what the virus is capable of because now I'm hesitant to even use that computer until I find a way to fix the problem and I'm considering reinstalling my operating system just to be safe.