I have read your post.
Please follow the below steps to resolve the issue that you are facing.
I understand that you are getting script error when McAfee tries to update the software on the computer.
Click "START" and then "RUN"
Type "CMD" and hit enter.
Type the following commands one by one and press enter to register the script dll files.
Then after the above steps please run a Windows update from the Internet explorer-->Tools-->Windows Update. If you see any critical updates please update the computer.
Please let us know if the above steps resolved the issue.