Hi BarryP01
to fully remove mcafee products, uninstall in settings -> apps -> apps & features and then run the mcafee product removal tool.
follow the guide from McAfee which also has the download link for the MCPR Tool
https://service.mcafee.com/webcenter/portal/ora...
once finished windows defender should switch on automatically.
please let me know if you have problem with it
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.