then maybe run one or all of the following free online scanners: A-Squared On Line Trojan Scan -- http://www.windowsecurity.com/trojanscan/
BitDefender On Line Scan -- http://www.bitdefender.com/scan8/ie.html
Ewido On Line Scan -- http://www.ewido.net/en/onlinescan/
F-Secure On Line Scan -- http://support.f-secure.com/enu/home/ols.shtml
House Call Anti-Virus http://housecall.trendmicro.com/housecall/start_corp.asp
Kaspersky http://usa.kaspersky.com/services/free-virus-scanner.php
Point being, you suspect that a virus messed up your system restore, therefore, until we can safely believe that the system is clean, we can't really try and fix system restore.
This would be 'my' first step.
Good luck,
Eddie