These instructions were actually used on a test VM running Server 2012 R2.

You will need the Windows Server installation disc or any ERD that will allow you to get to the C:\Windows\System32\ folder and rename/copy some files.

If using the Installation disc:

• Boot from the installation disc.
• Click Next after the Windows Setup screen appears.
• Select the “Repair your computer” option at the bottom.
• Select Troubleshoot.
• Select “Command Prompt”.
• Navigate to the C:\Windows\System32\ folder.
• Rename the sethc.exe file:

ren sethc.exe sethc.ex

• Make a copy of the cmd.exe file using the sethc.exe name:

copy cmd.exe sethc.exe

• Restart and boot to Windows Server.
• At the Login screen, press the Shift key 5 times, the Command Prompt will launch instead of the Sticky Keys window.
• At the command prompt, update the administrator password:

net user Administrator NewPassword

This has been tested on Windows Server 2008, 2008 R2, 2012 and 2012 R2.