Welcome to the Seven Forums.
Let's see if it is related to McAfee.
Just as an experiment, please download MSE
. Don't run the installation file, just save it to your desktop.
Disconnect from the internet and uninstall McAfee... restart and install MSE. When MSE wants to get its updates, please re-connect to the internet.
If you prefer McAfee, you can uninstall MSE and put it back on after we finish solving your problem.