I'm unclear if you are running both MaCafee and MSE concurrently? We see lots of problems in systems running MaCafee - when we see these problems, they are almost always solved by installing MSE instead.
I would recommend uninstalling MaCafee completely, installing MSE and then doing this:
1. Click Start
2. In the search box, type cmd
3. In the list that appears, right-click on cmd.exe and choose Run as administrator
4. In the command window that opens, type sfc /scannow
and hit enter.
Report the output once it finishes.