I work in the AV software industry, so if you can give me some details of what was detected and the location I should be able to help,
Meanwhile some handy tips for scanning:
Run your scan in Safe Mode (F8) if your AV will support it. Delete you temp internet files and contents of the %TEMP% and TEMP folders first as this will save time an dget rid of a lot of dross, malware is often found in the system restore folder and some AV software will not remove it , so turn it off, restart and turn it back on and the nasties are gone (as are your last restore points!)
Have a look in Add/remove programs and uninstall anything you do not recognise, you can also use MSCONFIG as an alternative to delving in the registry and this is a good way of stopping any auto-starts used by the malware.
Finally never open email attachments from someone you do not know or are not expecting something from, delete the mail instead, close the preview pane if you use one as many explits use this as a mechanism for launching malware, and remember, Micorosoft does not send out emails to mortals like us!
PM if you need to know more, I have a generic cleaning paper I wrote a while ago that covers this and loads more if you need it
Cheers