passwords - Windows 10: Account removed from Administrators group, how to recover?

Situation

• Windows 10 Pro, 64bit


• Removed letter assignment from CD drives, don't use them regularly


• By mistake (without thinking, that is) I removed my account from the Administators group


• Can't remember the password for the "administrators" account


• Can't install anything (need adminstrator rights)


• Tried burning Hiren's Boot CD, can't, removed letter from CD drive, see above

I'm out of ideas, and my mind is somewhere else, anyway.

So, can someome please help?