It's because you disabled UAC. No is admin in Windows 8.
Disabling UAC won't make you true admin, it will drop you down to a lower account.
UAC is part of Windows security system, and can't be disabled.
To me it seams that you did not give Windows 8 a chance, and you already wanted to put Windows 7 in the first place, and you were just trying to find an excuse. So, now your parents are stuck with WIn7 due to your close mind set. This is exactly the same behavior with people going "XP for life", because of UAC system. It is a system to provide a serious level of protection which so far has not been by-passed since it's introduction in Vista (good work Microsoft), and you decide that your parent should have none of that, and should run as true admin all the time.
Switch to Linux based OS, and tell how everyone you like running as root.
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