For problems with uninstalling Symantec products, such as Norton Antivirus, Symantec recommends the following procedure: Link
In case of problems with the automatic uninstallation of a McAfee virus scanner via Control Panel / Add or Remove Programs, you can also remove the product completely manually.
Manual uninstallation of McAfee VirusScan Enterprise 8i (English doc)
Manual uninstallation of McAfee VirusScan Enterprise 8.5i (English doc)
Manual uninstallation of McAfee VirusScan Enterprise 8.7i (English doc)