Infected with Superantivirus. How to remove it

I have Windows XP Home edition installed in my system. For some reason I do not know what happen McAfee is turned off on its own. It is not doing anything at all. I had tried to run Spybot and Ad-Aware in my system. After scan I found that there was around hundreds of virus located. I had restarted my system. I thought those would be removed. Later on reboot, McAfee prompted to updated. But it still fails to detect a virus. It is not catching any of them. It just prompt me to update it. In Start Menu I found SuperAntivirus installed. How does that was installed I do not remember. How to get rid of this now.

It looks you had hit by some rogue antivirus. There are tons of fake application that work on web and enters your system quietly. Try to re-install McAfee one more time. And then run a full system scan in safe mode. That would detect and clean the infection. That is the best way you can do. Or else the last option that remain is format your computer and re-install one by one everything. It would work properly.