Reset Windows 2008 R2 Server Admin password

To Reset Administrator Password in Windows 2008 R2 Server is a reboot and a few steps:

• Boot from the Micrsoft Windows Server 2008 DVD
• From the Install Windows menu, click “Next”.
• Select “Repair your computer”
• In the System Recovery Options, select the Operating System instance that you wish to repair and click “Next”.
• Select “Command Prompt”. The
• At the command prompt, run the following commands:c:
  cd windows\system32
  ren Utilman.exe Utilman.exe.old
  copy cmd.exe Utilman.exe
• Reboot the server allowing Windows to load as normal
• At the logon screen, press Windows Key + U.
• As the command prompt, enter the following command: 
• net user administrator New_PASSWORD
• Log into the server with New_PASSWORD
• Reboot into the repair command prompt

c:

cd windows\system32
del utilman.exe
copy Utilman.exe.old utilman.exe

Reboot and enjoy