If there are no Administrator accounts on the system, you can boot to Safe Mode to access the Built-in Administrator account. From this fail-safe account, you can force-reset your account's password.
- On the login screen, click the Power Options icon, then hold down the Shift Key while you click the Restart option. Keep holding shift until the screen says it is restarting.
- On the first screen that appears, select Troubleshoot, then select Advanced Options. Finally pick Startup Settings and click the Restart Button.
- On the next screen, press the Number 4 Key to choose Safe Mode.
Now that you are in safe mode, you can use the built-in backup Administrator account to perform you necessary recovery. The built in Administrator account should not be used for any other purpose, or it won't be available in situations like this when you need it.
- At the login screen, click the Arrow Icon and select the Administrator account.
- After Safe Mode starts, press
+W and open Control Panel / User Accounts. - Select Manage another account and select the account you wish to change to an Administrator account. You can also use the Change Password option here to reset the other account's password.
When you're done, restart the computer normally.