Ok there might be a solution to this. Ok first there is some questions?
1. On the first partition( the one with fat now on it) is just his o.s installed on it?
2. If it is not just his o.s. would he be able to lose the info on that particular partition?
3. And if he loses the info on that partition would he be able to get it back easily?

But ok here comes a few solutions:

1. Try inserting the xp disk so that it can boot and try it to use the last good known confuguration.
2. No here comes the tricky part. Get a 98 boot disk. Let the machine boot with the disk and choose to boot with cd-rom support. When it has booted enable smartdrv from your a prompt( this is just so that it runs a bit faster). Then change to your c prompt and type in format c:\q form quick formatting of the c drive(this is the part where he loses the info on his first partition). Then when finished with the formatting type in at the command prompt( md winxp ) this should create a directory winxp on your c drive. Then type the corresponding drive letter of your cd-rom at the prompt to change to your cd-rom. Type in at prompt dir/w/p and enter. This should give you a directory listing of what is on the cd-rom. I cant remember the directory in wich the cab files are place but search for them by typing cd (and the directory name) when you have cab files copy the directory where they are placed to the directory you made on your c drive by typing the following this is just an example: copy d:\cab to c:\winxp. It should start copying the cab files to your directory on your c drive. When it is finished go back to your c drive by typing c: at prompt and then type cd winxp wich should open the winxp directory on your c drive. Just type in setupnt or ntsetup this would start the xp setup from dos. Run the setup till you get to the part where it asks you where you want xp installed and it would give options.If you want to format yout drive and convert it to NTFS. Choose that option on the c drive. After it converted the c drive to NTFS it will ask you to reboot. Take out all disks and reboot. It will automaticly take you back to the setup after you rebooted. Then continue with the setup it will ask you again where it should be installed and choose again the c drive but this time with the option to leave the file system intact. Then continue with the setup.

I can actually do this and any computer shop could do it. It is just very difficult to explain in words and over the internet. I hope this helps and if you have any questions feel free to ask. And if I can ask is there any forum member that can help me if I made a mistake anywhere please let me know?
Best of luck to your friends computer <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />