I have a friend who suspects that he may have gotten an infection via email in his Yahoo account. Yahoo suspended his email abilities for 48 hours, and of course was not specific about why. I told him most likely it may be a virus or Trojan problem that McAfee missed. He has the McAfee protection suite on his Vista laptop. If he wanted to run Kaspersky’s scan will McAfee block him? If McAfee blocks the scan how would he disable it? Anyone got any advice. McAfee came with laptop and he doesn’t want to change or get involved with the whole uninstall process. Anyone got any words of advice, I’ve always come here with a problem and not been let down once! You guys are the absolute best!!! ;D
I recommend ESET Online Scanner (NOD32) over Kaspersky. With ESET’s scanner you have the choice to have any infection removed, Kaspersky’s scanner wont remove infections.
Try avast! Virus Cleaner - free virus removal tool
Try SUPERAntiSpyware free version, it removes trojans & other malware. 
The avast virus cleaner is for a specified number of true virus/worm infections and unless they have one of those it is unlikely to find anything.
The SAS recommendation is good, but with a suspected infection I would suggest that when it is installed, go on-line and update it so you have the latest signatures, etc. and then reboot into safe mode and run the scan from there.
To do an on-line scan just stop mcafee during the scan and re-enable afterward.