There are different ways to reset a lost local administrator password on a Windows system.
If you have a physical access to the machine, you can use a very useful boot disk and follow these steps:
At the first screen press “ENTER” to continue.
At “Step ONE” select the partition (by number) where Windows are installed (e.g. “2”) and press “Enter”.*
*Commonly it is the first and larger partition on the list, if you have only one hard drive on your system.
Leave the detected registry path (C:\Windows\System32\Config) and press “Enter”.
At “Select which part of registry to load” question, type “1” (Password reset) and press “Enter”.
At “Step THREE”, type “1” (Edit user data and passwords) and press “Enter”.
At the next screen, you can view the list of all the accounts on your computer. Type the Username of the account that you want to perform changes or leave the default entry (Administrator) and press “Enter”.
At the next menu (User Edit Menu):
Type “1”: To Clear (set Blank) the selected account’s password.
Type “2”: if you want to set a new password to the selected account.*
Notice*: I prefer to change an account’s password in Windows , after using option”1” to clear the previous password.
Type “3”: if you want to promote the selected account to Administrator. (Add to Administrator Group)
Type “4”: if you want to Enable the selected account or the hidden Administrator account (if it is disabled).
When finished making your changes type “!” (Shift + 1) and press “Enter” to quit editing selected user.
At the next screen, press “q” to quit the offline password editor utility.
At “About to write file(s) back” question, type “y” (yes) and press “Enter”.
If you want to try again, if the process somehow failed, type “n” and press “Enter”.
Press “CTRL+ALT+DEL” to restart your computer.
Pull out the Boot CD from your CD/DVD drive and boot to Windows.
Normally now you should be able to logon to the edited account without password.
- Boot from Microsoft Windows Server 2012R2 DVD/ISO.
- From the Windows Setup menu, click “Next”.
- Select “Repair your computer”.
- Click on “Troubleshoot”.
- Under Advanced options, click “Command Prompt”.
At the command prompt, run the following commands:
c: cd Windows\System32 ren Utilman.exe Utilman.exe.old copy cmd.exe Utilman.exe
- Close the command prompt, remove DVD/ISO and then reboot the system.
- The server should now boot and present the logon screen.
- Press Windows Key + U.
At the prompt you can change the password, by typing the following command:
net user administrator Password123
This will set the password for the Administrator user to be Password123 (case sensitive).
Now repeat the DVD/ISO boot steps and open command prompt above and run the following:
c: cd Windows\System32 del Utilman.exe ren Utilman.exe.old Utilman.exe