Just got a virus. I was stupid - but what can I say?

Neither Avira, Kasperky, HitManPro, nor RogueKiller has been able to detect how the virus is showing back up. I have found a new partition on my hard drive. It is only 16MB in size. You can not see it via Disk Manager. The way I found it is with MiniTools. I can not make the partition available or active. So I formatted the partition and I am going to delete it. This probably needs to be looked at because it is a new problem I have not seen before.