It says the Administrator (me!) disabled it. How do I enable regedit? Please help!
Try also Re-enable
will fix also some other process if you were attacked by malwares and they disabled those vital process
This is a fairly common indiction of malware. Most skiddies will disable registry editor so that you can't find the key in which the infection is present.
Download & Install RegistryFix. Once it fixes the issue, restart. You should have access to your registry editor again.
Although this could be an innocent curruption in Windows, I suggest installing an anti-malware application and scanning for malware. One such scanner is Malwarebytes. If you do scan, be sure to update it first and run a full scan.