bootsect /nt60 drive_letter: /mbr

C:Windowssystem32>bootsect

bootsect {/help|/nt60|/nt52} {SYS|ALL|<DriveLetter>:} [/force] [/mbr]

Boot sector restoration tool

Bootsect.exe updates the master boot code for hard disk partitions in order to
switch between BOOTMGR and NTLDR.  You can use this tool to restore the boot
sector on your computer.

Run "bootsect /help" for detailed usage instructions.