You know, it is no wonder people have such an ambivalent perspective of AV companies.
On the one hand, they all provide free services to the benefit of everyone. Every AV-protected PC is one fewer target.
On the other hand, they seem like pricks when they:
(a) accidentally bork thousands of PCs - which, to be fair - are highly-publicized but extremely rare occurrances, or
(b) Seem to intentionally make it damn-near-impossible for the average Jane to remove their unwanted AV product - which often comes pre-installed - from their own PC that they paid good money for.
Now, we all know they need to make money like everyone else, and AV is not an easy business. But try and lose more gracefully, people!
This is so pervasive that McAfee and others have resorted to creating "removal tools" specifically designed to uninstall their software. Which makes them just about the ONLY companies in the world who cannot figure out how to accomplish this, without error, using the built-in Windows un/install tools that have been around since - well, Windows itself.
If you do get a mysterious, uninformative and seemingly unresolvable error - like, say "Navigation to the webpage was cancelled" while trying to uninstall McAfee, it just raises more questions than answers. It says you can "Refresh the webpage", but you seemingly can't - are you doing something wrong? Did it uninstall or not? Is it still working or not? How do you check? How can you know?
Anyway, the McAfee Removal Tool seems to take care of the issue by completely removing McAfee AV. Just be sure you download it from a McAfee site, and not some sketchy file-sharing site that might have a Trojan horse nasty masquerading as the legitimate removal tool.