If McAfee isn't installed I can't see how it could be blocking you from web pages unless you still have SiteAdvisor installed or perhaps Parental Controls, but to make sure it isn't installed run the MCPR cleanup tool listed under Useful Links at the top of this page and reboot immediately afterwards.
You don't mention any details of your operating system, service pack or what protection software you do have so it's difficult to know what to suggest but you might want to consider running a couple of the free tools listed HERE, such as Stinger, Malwarebytes free etc.
Why have You decided mcafee is guilty for Your problems? Why not other AV?
After a month I would consider this subject closed.