Remove Sasser Manually
Disconnect your computer from the Internet.
Boot in Safe Mode by pressing the F8 key during startup.
Navigate to your Windows directory (c:\WINDOWS or c:\WINNT) on your hard drive.
Look for a file named AVSERVE.EXE. Delete it.
Click on the Start menu and select Run.
Type "regedit" (without quotes).
Navigate to the following Registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
In the windows to the right, look for a value called avserve. Delete it.
Exit RegEdit.
Reboot.