Replacement for FDISK /MBR

I have an Acer Aspire M3400 with Windows 7 pre-installed. I have installed a second internal SATA hard drive on which I plan to install a second operating system. This will involve using Grub to overwrite the boot partition in Windows 7. If Grub fails and I can't get into Windows 7, is there anything similar to FDISK /MBR which would enable me to restore the boot partition and get back into Windows 7 ?

You might try Ultimate Boot CD or Hiren's Boot CD.

Probably the best is EasyBCD. Check it out!