Hi there,
I had more or less the same problem and microsoft has a fix for it.
here you go:
Microsoft® Windows® Malicious Software Removal Tool (KB890830)
Install, scan and look what you can do from there on (mostly they present to scan your computer with decent anti virii software after the tool has finished).
http://www.microsoft.com/downloads/details.aspx?familyid=ad724ae0-e72d-4f54-9ab3-75b8eb148356&displaylang=en
note on the side:
Brief Description
This tool checks your computer for infection by specific, prevalent malicious software (including Blaster, Sasser, and Mydoom) and helps to remove the infection if it is found. Microsoft will release an updated version of this tool on the second Tuesday of each month.
Be sure to update it and scan from time to time after using windows live care or any other software, even mcafee on my O.S. is updated weekly and didn't find trojan.frauder, this tool did. 
Hope this helps buddy !
Kind regards,
Gunther.