need a good free antivirus. PC infected

[Ryendal]

Hello, I have a virus. I used AVG and he found one, but after I reboot, the virus is back ...
I used also a link " trend micro " with a free scan. I used it few month ago, and it was great, but it seems to not work properly now ...

If you have a good free antivirus to sugger me.

Thank you