How to reset the Domain Admin password for Windows Server 2008 / R2 with only a Windows 2008 Server installation media if youre the type to lose passwords.

1.    Boot into install disc
(Windows Server 2008)
2.    Select language options and click next
3.    Click Repair (bottom left) > Next
4.    Click Command Prompt
5.    (cd to C:\Windows\System32)
6.    >move Utilman.exe Utilman.exe.bak
7.    >copy cmd.exe Utilman.exe
8.    Restart and boot into server 2k8
9.    Keyboard Shortcut : Windows + U
10.    Command prompt opens
11.    >net user administrator (password)
12.    Or just type ‘net user’ to see syntax help and figure out what you want to do

Obviously rename the files back once you are finished to avoid any issues down the track.