Hi
Is this a laptop with a recovery partition?
If it is I'd recommend creating a bootable Ubuntu disk, boot into the computer using it, and backup all of his important data to an external hard drive and then use the recovery partition to restore the computer back to factory state.
If he doesn't have a lot of stuff you could use the USB Stick to transfer the data to another computer temporarily, you can't use the disk drive because the computer is running from it.
The Ubuntu disk will give you a file manager, browser etc, everything you need to save the information from the Windows install and will not be affected by the malware.
http://www.ubuntu.com/download/alternative-downloads
I use version 12.04 which seems to be able to boot anything.
Use ImgBurn to create a bootable DVD from the ISO file.
It sounds like this has gone beyond the remove the malware point.
You do have to have some access to the computer to do that.
It may be possible to create a bootable repair disk, but it's not something that I have experience with.
Maybe someone else here can suggest something.
I haven't had any luck using Windows repair functions in cases like this, like restoring from the built in restore partition Windows will remove all your data, if you want to get rid of the malware.
Mike