A greyed out option in McAfee VirusScan means that you are unable to make a selection. If you can't click on one of the options, you are not able to run a scan, leaving your computer at risk for viruses. To remedy the disabled buttons, troubleshoot the program and determine the underlying cause of the greyed out options.
Unlock User Interface
You may be able to restore the options on McAfee VirusScan if the user interface is locked, which could cause the buttons to appear greyed out. On the program's icon in the system tray, open the menu by right-clicking. Choose "Virus Scan Console" from the available options, then select "Tools." Within the Tools menu, choose "Unlock User Interface" to unlock the interface and restore the greyed out options. If you are unable to choose this, your system administrator may need to perform the action.
Contact System Administrator
Further troubleshooting when your VirusScan options are greyed out should involve your system administrator, if you have one. The computer's registry may need to be altered, which is something that your system administrator can do. If you're using a computer that is in a network or under a system administrator, that administrator may be able to perform more extensive troubleshooting since that person has more access to the computer than you do. Don't attempt to alter your computer's registry unless you are the system administrator.
The permissions for McAfee may be set so that only certain users can choose options in the program. Open the registry by choosing "Start" then "Run" and searching for "regedit" in the search box. Find VirusScan under [HKEY_LOCAL_MACHINE\Software\McAfee], then right click on that and select "Permissions" from the menu. Check that each user has full permission, which will resolve the greyed out options, and make changes to provide full permission if those options are not selected.
Contact Customer Service
If unlocking the interface and altering the registry have not resolved the issue, contact McAfee customer service. A customer service representative may be able to further troubleshoot your machine and assist you with making additional registry changes, if necessary. If you're using a computer that is not your own, contact your system administrator or technical team for help troubleshooting the greyed out options on VirusScan.