not tooo bad..
just make sure you run your virus scanner repeatedly after each other as they manage to replicate themselves during the initial scan, do it till you get 0 found, and reboot windows also before scanning again (might re-appear)
worst virus i came across was Hacdef.c
it stopped IE browser working, also connected to a server and downloaded other viruses that downloaded spyware that downloaded porn without me knowing (700mb)
it also prevented me using certain antispyware and virus programs like ad-aware lavasoft, spybot search and destroy by removing them from the desktop and then prevented it running without closing it etc, removing it from the start directory
which made trying to kill it a pain in the arse.. had to reinstall windows in the end
