Did you run all the removal tools here: http://community.mcafee.com/showthread.php?t=168100
Then run the MCPR removal tool in my signature.
Failing all that you'll have to use the registry editor to remove all traces.
Go to Start/Run and enter regedit and click OK.
A page should open with the top left hand corner looking like this:
if for some reason it's expanded, collapse it and then highlight My Computer.
Go to File tab and click "Export" and send the registry to your desktop. This is in case something goes wrong. It can then be rebuilt by simply right-clicking that desktop item and selecting merge.
Now click the Edit tab and then "Find". Enter "McAfee" (minus the "") then click "Find next" (or hit the enter key).
Whatever is found, right-click and delete.
Hit your F3 key for the next instance and keep going until all entries are gone.
If one says it can't be deleted this is where it gets complicated. You have to then find which key on the left column pertains to it and right-click/Properties/Permissions and give yourself permission.
If all is successful that entry could not possibly remain and you can then delete the registry backup.
This has to be done when signed in as an Administrator by the way.
You may have to repeat it using "Network Associates" and/or "NAI" minus the "" - it can be a long process.