Cannot enable McAfee VirusScan for Windows

McAfee VirusScan is currently disabled and cannot be enabled successfully.

Problem

McAfee VirusScan for Windows is installed, but VirusScan is disabled. Clicking Enable On-Access Scan fails to enable McAfee VirusScan.

The McShield service is in a paused state. When you click Resume, the McShield service starts, but then immediately reverts back to a paused state.

Remove and reinstall McAfee VirusScan.

To remove and reinstall McAfee VirusScan, do the following:

If you don't already have the installer file, download McAfee VirusScan.
Click Start > Control Panel.
Do one of the following:
- In Windows XP, double-click Add or Remove Programs.
- In Windows Vista (Default View), click Uninstall a Program.
- In Windows Vista (Classic View), click Programs and Features.
Locate McAfee VirusScan Enterprise in the list of programs, and select it.
Do one of the following:
- In Windows XP, click Remove.
- In Windows Vista, click Uninstall (near the top of the window).
When asked "Are you sure you want to uninstall McAfee VirusScan Enterprise?" click Yes.
Follow the on-screen prompts to uninstall McAfee VirusScan.
After the uninstall finishes, restart your computer.
When your computer restarts, install McAfee VirusScan using the file you downloaded in step 1, above.