If you're stuck, check out some of the links on my site -
If you're not sure if the system is clean, try to stay offline for 2-3 days to let the virus signatures catch up, then download the latest sigs / spyware definitions from another machine and install them with your main system remaining offline.
I've just had to do this for a colleagues' fathers laptop - an initial scan showed 18 viruses, mainly of the bank account stealing sort, and another 20 traces of the same appeared in Spybot S&D.
A scan a couple of days later came up with a couple more things, but these seemed to have been rendered useless by the earlier scans.