McAfee SecurityCenter is inoperative in any of the various safe modes but you can still initiate a scan by right-clicking the taskbar icon and selecting "Run a Scan". There will be no indication that anything is happening but if you hover over the taskbar icon you will get a progress report.
Follow the guidelines in THIS document.
If that doesn't help get the FREE version of THIS software and update it before running (important). Let it remove everything it finds and reboot if asked to to complete the scan.
*******Meanwhile, and this is very important. It is vital that you install SP3 in order to continue to be supported by Microsoft for security patches. They stopped supporting SP2 and under on July 13.
There have been numerous updates since SP3 so keep updating with all critical and non-critical updates via Microsoft Update (as against Windows Update) as it will update everything.