I had to move 2 laptops from McAfee to Norton.
One worked OK.
The second one didn't. It would not allow me to uninstall McAfee, but it installed Norton anyway.
When I clicked uninstall McAfee nothing happened. No error messages, just nothing. So its still there? What is going on?
It may be that McAfee has been uninstalled but some of the dross has been left behind.
Assuming that you are using a Windows operating system follow the link to uninstall McAfee
McAfee KB - How to remove McAfee products from a PC that runs Windows (TS101331)