Disclaimer: This guide is a combination of two tutorials I have read regarding the subject, each somewhat different, but taking the useful parts of each to create a better solution.  I am writing this guide to see if I can help others in a similar situation, however I cannot be responsible for anything that happens as a result of it.  All I can say is that this worked for me, and you should consider your options before trying anything.

The Situation:

• You recently used a service pack 1 disc of Windows XP with BootCamp on Leopard.
• When your computer restarts, your screen is white/blank; nothing happens except Apple noise when turned on.
• You have no real options to do anything; aka booting from disc, single user mode, disc selection, etc.
• Upon restart and holding the option key, you see your mouse, but the computer freezes shortly after.

If your situation sounds like this, hopefully this might be of help to you.

Needed Supplies:

1. A FireWire (iLink) cable. (Male to Male connector; I used 6-pin version, bought at MicroCenter for about $20)
2. Another (working) Mac with Leopard and a FireWire port. (Hopefully this isn’t hard to find for you… Maybe ask some friends?  I’ve also read about people who have used an External Harddrive that connects through FireWire with Leopard installed on it)
3. A really great program called TestDisk. (Use from the working computer; You can find this program here, and don’t worry, it’s free.)

That should be all you need. When you’re ready, cautiously being the steps below.

What to Do:

1. Turn off both the working and non-working computers.
2. Turn the working computer on while holding the T-key.  If successful, you should see the FireWire symbol floating around the screen, indicating that you are in Target Disc Mode.
3. Now turn on the non-working computer, and hold the Option-key.  After a few seconds you should see your mouse and an icon that Idenitifies the other computer’s connection to you.  Quickly click that icon before your computer freezes! (Both the Icon and the arrow beneath it I’d say) (Also, don’t worry just yet if nothing shows up except the mouse when you restart holding Option-key.  The same thing happened to me, but just keep trying it over and over until you see it.)
4. Once you’ve clicked it however many times and the computer has frozen, turn off the non-working computer and restart it once more.  The computer should boot up using the hard drive of the working computer!
5. When your computer logs in, it will say that there is a “DIsk that cannot be read” and give you the options to Initialize, Ignore or Eject.  Choose Ignore. (This is your non-working harddrive FYI)
6. Navigate to Applications->Utilities->Terminal and open Terminal.
7. You should have downloaded TestDisk as mentioned in the supplies list (if not, download it now!), so you must change directories to the TestDisk directory in Terminal.
   Type cd followed by a space, and drag the downloaded TestDisk directory onto the terminal. Press Enter/Return. If that worked, you should be in the TestDisk directory.
8. Now you must begin TestDisk.
   Type sudo ./testdisk
9. TestDisk should now be opened.  If you need to, make the terminal window bigger like it says.
   You’ll be given a few options…
10. Choose “Create” for the log file.
11. Select your HardDrive. (Typically /dev/disk0)
12. Choose “EFI_GPT”
13. Choose “Analyse”
14. Choose “Quick Search”
15. It’ll now be searching and will show progress and such; wait for it to complete.  When it’s done, check the listed partitions for accuracy.
    You should have one labeled EFI (about 200MB in size), one labeled BOOTCAMP, and one for for Mac that’s the largest.
    If that’s correct and you feel confident about it, press enter to continue.
16. Choose “Write” and follow any instructions.  This will write your hard drive partition map.
17. End the TestDisk program. (Quit)
    When I quit the program, my drives were on my Desktop. (Macintosh HD, EFI, and BOOTCAMP) If yours aren’t, I would try using TestDisk again.
18. Shut down the non-working computer, and then turn off the other one that’s connected through FireWire and remove the cable connecting them.
19. Start up the non-working machine, and it should work alright now and startup. (At least that’s how mine was)
20. When you turn on the computer and login, you’ll notice the other two disks (EFI and BOOTCAMP) are on your Desktop as well as Macintosh HD. (Optional) To fix this, I just opened up Disk Utility (Applications->Utilities), selected my hard drive, went to the Partition tab, and hit the – (Minus) button for the EFI and BOOTCAMP drives.  I then dragged my “Macintosh HD” partition’s bottom-right corner to fill the whole space.