OK as I see it
1 Father has a 3 licence account what do you have?
2. You want to move to his account this is easy really support should have showed you you did not need to uninstall your software.
Actually rereading your post I am a tad confused were you saying you were on his account and he could not install? Can you elaborate.
Assuming you have software installed and working you use the subscription repair tool; to move to your fathers account.
You follow this on your Pc and when asked fill in details of your father's account. Done this many times fixing up account issues with my kids installs.
Support can do it for you That I am sure.
That said You uninstalled unsure why and now cannot reinstall correct?
When you uninstall always use the windows removal methofd reboot and run MCPR. that way the old licence is removed. Running MCPR leavs the old licence still in the account to be a duplicate for ages.
Ok try this run MCPR again
reboot and run
Rename your PC
reboot and retry installing the software. Ensure you have no other AV installed including Malwarebytes etc.
See how this goes
Okay, I will explain in full detail what happened.
1)Somehow my father and I ended up with 2 McAfee accounts, no idea how that happened but it meant we were payign $160 for my lisence, his lisence, and 2 others on his 3 user one that we weren't using.
2)My father said that we should get rid of my account and then move me over to the 3 user account so the other lisences get used.
3) I download the 3-user McAfee
4)Tried installing it, as it was installing it removed previous McAfee
5)Then the pop up at the end said what it says in this thread title
I did end up getting to Live support and they were helpful, took over my computer, but the live chat person said I did not have WIndows service Pack 1 on my computer, which is odd because I just updated my computer, don't know how it could have not installed.
I tried going on the WIndows website to download it but there's so many files I don't know which one to download (my computer is WIndows 7 64-bit)
Also for some reason I cannot run MCPR, everytime I try to it crashes when I press "start"
Windows update should pick it up does system in control panel say you have it or not?
Definately the subscription repair tool will work as will installing from his account but seems you need to neaten windows up first.