Hi Teck, I've encountered this problem you faced before and it is surprisingly easy to fix (unless you have a hard disk that is already failing). You will need your Windows XP CD to do this.

1. Boot from your Windows XP CD. You might need to change the settings at the laptop's BIOS. Most modern BIOS nowadays support a "boot menu", where you can specify which device to boot from without changing the CMOS settings. It is usually tied to the F9 or F10 keypress before the machine boots.
2. I do not know if you have done a fresh Windows XP installation before, but if you haven't, what happens now is that the Windows XP installer will load the various drivers and system files in order for the installer to fully run. Initially it will ask you to press F6 if you need to install 3rd party hard disk drivers and F2 to run automated recovery. Ignore those and wait till you reach this screen:
http://www.simplyguides.net/images/g..._console/4.jpg
3. Notice the second option: "To repair a Windows XP installation using Recovery Console, press R." Do what it says; press R.
4. You will be asked to press Enter if you want to use a custom keyboard layout. Either wait for the 5 seconds to expire, or press Esc to get this following screen:
http://www.simplyguides.net/images/g..._console/6.jpg
5. Normally you should only see one installation as in the screenshot, which is usually at C:\WINDOWS. Press 1 as in the screenshot to select that installation.
6. There is an Administrator account built-in in Windows XP and is usually transparent to the end user unless he/she activates it and uses it. By default there is no password for the Administrator; just press Enter. If you are unable to log in without a password, you should ask who has set the password before, or call your laptop service personnel.
7. Now, type the following command, fixboot, as in the screenshot. This will fix your corrupted boot sector on your hard disk.
http://www.simplyguides.net/images/g..._console/8.jpg
8. Type exit and your laptop will reboot. Remove the installation disk and your system should boot as normal.
9. If your system still does not boot, you might want to try fixmbr instead of fixboot at item 7. If you have multiple operating systems installed in your hard disk, you will need to reconfigure them to appear as a choice in the boot menu again. You should only do this if fixboot really doesn't work.
http://www.simplyguides.net/images/g..._console/7.jpg
10. If these steps still do not work for you, or if the problem returns time and again, you might have a failing hard disk, or you have a virus in your computer that is corrupting your boot sector. Either scenario would justify sending your laptop for service, especially if you'd like to avoid all the possible headaches and possible voiding of warranty associated with fixing it manually.

Hope this helps!

P.S. If you mean the $20, just PM me and I'll give you my e-mail.

Dang! i wish i saw this sooner!

Technically, it wont work, cause its a desktop, not a laptop... and she doesn't have her boot disk... SOOOOO, hopefully the Geek Squad from Best Buy can do something, her dad done called about it and she's set for her computer to be fixed this week.

Wait what are you talking about. I just did it on my destop 2 days ago! You dont need a boot disk either. Any windows xp disk of any version, copied or legit, retail or oem, will work. What the above poster said will work and dont take it to the geek squad and waste your money, just do what the above person said. They are 100% correct.

What nizzy1115 said is true, you could use any Windows XP CD to do this. But if you don't then I guess you will have to do with traditional servicemen. But really now, you don't have a Windows XP CD lying somewhere?

As sad as it is, no, I don't have ANY Windows XP disks lying around, I would buy OEM, but its expensive in a way. Hell, do you think eBay could help me in this cause (of finding a cheap Windows XP disk?)

You could try that. Alternatively you could search for a torrent that gives you an ISO for the Windows XP CD. Then you can burn that out for your use. So long as you have a legal CD-Key, you own the right to have your own Windows XP CD.

'Eh, okay, so ummmm, where can I find me a copy of the Windows XP software... and how hard is it to add it to an CD? Just take the files and copy to the CD? Also, is there any "keys" thats I need to add to the CD to make the softwware run nicely.

I would love to help you here, but it seems that this thread is getting into the realm of illegal copyrighted infringment material.
However if one was wishing do such a thing, (which you deffinatly mussent, or anyone else for that matter) you would download a bit torrent client, such as azureus and install it (just google it), then you would go to a bittorrent website, such as torrentspy, or thepiratebay, and search for windows xp and download the file. Once the torrent loads into the bit torrent client (azureus) and finishes some time later, it will likely be in the format of an image file, (iso, img, etc.). You would then need a cd burning program that can burn cd images, such as nero 7, and you would burn the image to the disk. (Again research on google if you have more questions into this). After it is burned you have a completly real (or as real as it gets) windows xp cd (you already have the cd key but it is not needed for your application) to do what the directions state for repairing the master boot record.