Download any of the System Rescue tools using a clean computer:

VIPRE Rescue
Avira AntiVir Rescue System
Kaspersky Rescue Disk
BitDefender Rescue CD
F-Secure Rescue CD
Dr.Web LiveCD

You need to burn the file in a blank disc and use to boot the computer. It will scan the computer before Windows logon which means the rogue program or any malware will be removed, if found by the scanner.