Hi KathleenR, welcome to 7F
If you are sure you will not be re-installing it later or elsewhere I would.
Just using Add/Remove Programs in Control Panel will leave fragments of the program, that can lead to problems later on down the road.
Quote from your link:
IMPORTANT: You must uninstall using the Windows software removal utility (Add/Remove Programs in XP, “Programs and Features” in Vista and Windows 7) before running MCPR. Failure to do so can result in the number of your licenses being incorrectly counted.
If you are not concerned about the licenses, even if you are, you seem determined.
Run the uninstall from Add/Remove, and then the MCPR.
Think of the MCPR as a final step in removing anything that was left.
If you had a subscription, your only concern would be having any part of it pro-rated, and refunded back to you.
I would get that straightened out before you remove the program, unless you can find them in a McAfee log file.
So in that sense you would need to know the license numbers to interact with McAfee Customer Service.