If the infection is being found in the System Volume folders (System Restore), then those files are locked. In order to remove the infected files, simply disable System Restore temporarily, restart the computer, then re-enable System Restore.. A rescan should show the infection to be gone.

How To Disable System Restore

If the file is not in the System Volume folders, then please let us know where it resides.. You may need to use the Recovery Console from Windows XP to delete the file manually, IF you're using XP or another method if using a different operating system.

Hope this helps.