Anak said:
It could be that those accounts, the built-in and regular admin are corrupt, try that sfc cmd and if as you say the netbook has been out of service for awhile run that chkdsk before the sfc scan that ICiT2 suggested.

It wouldn't hurt to try some troubleshooters but if you can't do anything from within control panel using those two accounts you could try by using a cmd line and make sure it's an elevated one.

See: How to run a Troubleshooter from the command line in Windows 10 I know it says w10 but I checked around and they should work in 7 and this site explains it best.

Listen, I have to take a break for awhile, my health isn't good, nothing too serious, your in good hands and I'll be getting your replies so if I can I'll post back.
First and MOST important get better!

I've added with both the commandline and Computer Management Snapin, which is why THIS buged me so much - I did mention that in the OP - thought I had.
I've gone through all the standard stuff, chk, sfc, removing admin account/re-adding etc and nothing worked. UNfortunately my registry backup program ERUNT - Yeah from WIn95 but still works a treat and has saved my butt many times, hasn't run since the beginning of last year or I could have gone back a few to see, even though I've NO idea when this started.
Soooooooo, I'll just use the Management Console - it's not as if I NEED that all the time.

GET BETTER!