|Glad to hear I'm your Hero, the link I gave was because you asked what malwarebytes was...hopefully you were enlightened with your search ;-)|
First of all McAfee is pretty lame to say the least.
If you want to get rid of your viruses try these free cleaners.
1- Trojan Remover
2- Hitman Pro
Run those till they are clean.
Now run these tools in this order:
1- rkill.exe (will stop malware from starting)
2- tdss killer (will remove a rootkit if it is lurking on your PC)
3- malwarebytes (run a full scan) remove all it finds.
I don't know if your vista is 32 or 64bit.
If the above clean your PC's problems I would suggest uninstalling McAfee and maybe even trying Avast Free as it has better real-time protection, auto updates daily and no scheduled scans...the choice is yours.
Some HELP in posting on Computing.net plus free progs and instructions Cheers