Built-in Administrator account is missing from my Windows 11 Pro system

Thank you very much for reaching out! As an Independent Advisor and fellow Microsoft user, I'm more than happy to assist you.

Have you deleted it accidentally by any chance? Please try the steps below:

1. Boot into Safe Mode and Attempt Activation
   • Restart your PC while holding the Shift key, then select Restart from the login screen.
   • Navigate to Troubleshoot > Advanced options > Startup Settings > Restart.
   • After restart, press 4 or F4 to boot into Safe Mode.
   • Once in Safe Mode, open Command Prompt as administrator (search for "cmd" and run as admin).
   • Run net user to list accounts again—check if "Administrator" appears.
   • If it does, enable it with net user Administrator /active:yes (note the capital 'A'—commands are case-sensitive).
   • If successful, restart normally and sign in as Administrator (it has no password by default; set one with net user Administrator *).
   • To disable later for security, use net user Administrator /active:no.
   If the account still isn't found, proceed to the next solution.
2. Re-Enable via Registry Edit Registry edits can cause issues if done incorrectly. Make sure to create a system restore point first via Settings > System > About > Advanced system settings > System Protection.
   • Boot into Safe Mode or the Windows Recovery Environment (hold Shift during restart, then Troubleshoot > Advanced options > Command Prompt).
   • In the Command Prompt, type regedit and press Enter to open the Registry Editor.
   • Select the HKEY_LOCAL_MACHINE key, then go to File > Load Hive.
   • Navigate to C:\Windows\System32\config (replace C: with your system drive if different), select the SAM file, and open it.
   • Name the loaded hive something like "REM_SAM" and click OK.
   • Navigate to HKEY_LOCAL_MACHINE\REM_SAM\SAM\Domains\Account\Users\000001F4.
   • Double-click the F value on the right. In the data, go to line 0038, change the value from "11" to "10" (this re-enables admin status).
   • Click OK, then go to File > Unload Hive to save changes.
   • Exit Registry Editor and restart your PC.
   • After reboot, run net user Administrator /active:yes again to activate.

Let me know if you're still having trouble.