1st thought is did you have another Anti virus installed before you installed Mcafee and did you use its removal software to clean up its files. They might be clashing with Mcafee.
Cause from Microsoft see http://support.microsoft.com/kb/2669244
This issue can occur if any of the following scenarios exist on your PC.
- You do not have permissions to the file or the file location.
- The file is on a location that is not currently accessible like a network location or an external drive that is not currently connected to the PC.
- The file has been moved or deleted.
- The file or shortcut is corrupt.
- The file may be blocked by Windows.
- Your antivirus software may be blocking the file. If this best to call tech support and get them to see this happening they should be able to sort it out.