OK here is what he needs to do.

First go to another PC and download and create the boot CD from the link below, then boot up the PC in question and go to the BIOS, set it to boot from the CD or DVD drive, load the new CD into that PC and re-boot it.

This will load a mini XP operating system (not a full OS) into RAM, it has software tools that will allow him to repair the MBR (master boot record) on the hard drive, the MBR is where that file is located.

It also has some good trouble shooting tools to find out why it happened.

Code:
http://www.hirensbootcd.org/download/