Yea, the computer that wasn't so bad had avast - which really helped, especially when I was able to do the scan on boot BEFORE the virus was able to launch itself in windows. Even spybot S&D wasn't able to launch before it on bootup,
. The one that I had to reformat had AVG.
The "Internet Security 2010" was particularly vicious. It disabled task manager access, alt+F4 shortcuts, closed down cmd.exe (command line/DOS) and said it was infected, interfered with other anti-virus scanners, etc. No fun at all. Quite a learning experience however.
Note to all: Don't let users have admin, for any reason, even if they're the only person that uses the computer
Also: Bootable Linux USB drives are handy, I've had one for a while and it has benefits.