Not sure what you mean by virus log but I assume you mean that VirusScan didn't install.
Do you have any other protection software installed? Have you experienced any strange activity in your machine or any pop-ups indicating spyware?
Please include the following information:
What is your operating system, service pack and are you up to date with Microsoft update? There are two ways of checking this. Go to Start/Run and type in winver then click the Enter key. Or, right-click My Computer in the Start Menu or on your desktop (or Computer in Vista) and select Properties. Post what it says.
What McAfee products do you have? Right-click the taskbar icon and select Open SecurityCenter and then click "View Details" or "About" at the lower right of the new window. Post the details from each module.
Inability to install can be caused by leftovers from previous installations.
Follow the instructions below to remove all remnants. Temporarily enable Windows Firewall first.
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 (MCPR.exe). This will remove all McAfee remnants from your computer. (You must have Windows 7, 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.