My computer has two accounts, one is the default windows admin account. The other is a standard user. I disabled the admin account using 'net user administrator /active:no' then signed out. Now my pc has NO active ADMIN accounts. The lockscreen no longer shows the admin account since it was disabled. Is there a way i can reactivate it somehow? I know my password for the disabled admin account, it's just that I have now deactivated the ONLY admin account. I tried netuser from the standard account but of course that does not work. Any ideas?
You may still logon to Windows using the local Administrator account, even if it is disabled.
You do this by starting Windows in Safe mode. Even when the Administrator account is disabled, you are not prevented from logging on as the Administrator in this mode.
When you have logged on successfully in Safe mode, re-enable the Administrator account, and then log on again.
For more details, see the Microsoft article
How to access the computer after you disable the administrator account.
By default the local administrator user is disabled. If your own user is in the Administrative Users group, you can still run an elevated command prompt without problems, and having the administrator user disabled is preferable anyway.
If your own user is not in the administrative users group, then you effectively locked yourself out. In that case, make backups and reinstall.
One thing you can try (but I doubt it will work) is logging in as your account, start cmd as admin, and if it prompts for credentials, enter Administrator with the correct password.
There are other things you can do, but that basically falls under the category: Hacking a windows computer, and that is outside of the scope of SuperUser.