1. Click the 'Start' button then type 'regedit' in the search box at the bottom of the 'Start' menu if you are using Windows 7 or Windows Vista. Press 'Enter.' In Windows XP, click 'Start' and 'Run,' then type 'regedit' in the dialog box.
2. Navigate to the 'HKEY_LOCAL_MACHINE,' 'SYSTEM,' 'CurrentControlSet,' 'Services' and 'mfeapfk' folders on the left side of the window. Click the 'mfeapfk' folder.

3. Double-click 'ImagePath' on the right side of the window.
4. Change the information in the 'Value Data' box from 'system32\drivers\mfeapfk.sys' to 'c:\windows\system32\drivers\mfeapfk.sys' and click 'OK.'
5. Close the registry editor and restart the computer. McAfee VirusScan Enterprise should now function normally.