How to Reset Your Forgotten Domain Admin Password on Server 2008 R2.
2- Restart the server and chose the boot option from CD.
2-click NEXT and click on repair mode your COMPUTER.
3-click on NEXT and SELECT COMMAND PROMT on NEXT and SELECT COMMAND PROMT.
4-.x:\SOURCES>dir ENTER (ALL COMMAND GIVEN BELOW)
c:
Dir (file not found)
D:
dir (file found Like-windows)
MOVE C:\Windows\System32\Utilman.exe C:\Windows\System32\Utilman.exe.bak