I noticed this morning that my McAfee On Access-Scan was disabled. (The shield in the system tray had a red-crossed circle.) When I opened McAfee, it was performing a scan, so it wasn't clear what was occurring. After some research, I found that the settings may have become corrupt. Here's the steps to correct: Go to VirusScan Console >> Help >> Repair Installation. Check the fist check-box to reset to the default settings. Click OK. This should do the trick.