Uh… from what I understood, that will not help him. His data is all there, its just that the boot loader can’t find the operating system. I’m not quite sure what he did, but I have a guess:
He installed GRUB to the MBR. This means that the MBR points to GRUB, which is located in /boot on Linux. When he uninstalled Linux, probably by deleting the partition from Windows, the next time he boots up, the MBR tells the computer to look in /boot for the bootloader, but it no longer exists, and thus he cannot get into Windows now.
Correct me if I’m wrong.
I myself did something similar to this a while ago (I was installing Xubuntu to an external drive, and I accidentaly installed GRUB to the internal HD. Upon finishing using Linux, I shut down, poped out the drive, and what do you know, my computer won’t boot. I tried putting it back in, but it was still totally screwed up.
I ended up fixing it using the Windows XP installation disk. You boot into a recovery console, and then you use the command fixmbr. You can google for more concise instructions. Keep in mind that this will make it so that only your windows partition is accessble, any recovery partition, or other operating systems won’t be.