What version of VirusScan is this? Double-click the taskbar icon to open Security Center, then click "About" in the lower right-hand corner and post the details of versions from each section. Include the DAT details from VirusScan too please.
Check that Windows is up to date. Check that you have the latest version of Internet Explorer and that it's set to default settings. McAfee relies on IE for functionality.
It sounds like your installation is corrupted so you have two choices. Try contacting Technical Support Chat directly, linked at top left of this page or in my signature, or try the following:
1. Uninstall all McAfee programs through "Add or Remove Programs" in Windows "Control Panel". 2. Use the MCPR tool, see this article: How to remove supported McAfee consumer products using the McAfee Consumer Products Removal tool (MC... This will remove all McAfee remnants from your computer. (you must have Windows Vista, XP or 2000 SP4 to use this tool) 3. Launch Windows Explorer and delete all McAfee files in "Program Files" but especially in "C:\Document and Settings\<user>\Application Data" and "C:\Document and Settings\All Users\Application Data". You have to set Windows Explorer to show all hidden files and folders (Tools > Folder Options > View tab). Just delete the McAfee folders even if they are empty in all the "Application Data" folders. Can be more than one! In Vista: C:\Program Files, C:\ProgramData and C:\Users\yourname\AppData\Roaming If you can't find these files don't worry. It just means that MCPR has done its job. 4. Reboot and redownload/reinstall your McAfee products directly from your account at the McAfee web site.