Need to reinstall XP and only have the original disk. Sure, you could install that, then install the latest service pack and updates, but that's a somewhat tedious process and you may run into problems, such as the fact that the original XP doesn't recognize all of your large hard disk. The solution is to "slipstream" the service pack files into the installation directory so that you end up with a service packed version of XP. Read more about that, and get a link to Paul Thurrott's detailed instructions on how to do it, here: http://www.wxpnews.com/H958GL/081104-Reinstalling-XP
Here is my (less detailed but easier ) version of how to slipstream a Service Pack into your older XP CD (posted for comparison purposes only of course )
The simplest way to create a Bootable Windows XP Pro or Home Installation CD Slipstreamed with SP2 or SP3 is to use Autostreamer. You point to your XP Pro/Home CD, the SP2/SP3 Service Pack .exe file, give it a path to write the .iso file to and off it goes. In 5 or 10 minutes you have a .iso file that you can burn to CD with almost any CD burner program you want to use. I used Roxio 7. There is a good freeware burner called DeepBurner which will do this also.
An excellent alternative is nLite. It allows you to merge SP2/SP3/Windows Updates into a new XP CD image that you can install from. Takes a bit of fiddling with but worth the effort since it also allows you to pre-answer all the questions asked during install so all you have to do is boot the new CD, select where you want to install, format or not and go to lunch. When you come back the install is finished and your are at the latest Service Pack and Update level. See here: http://www.nliteos.com/
) version of how to slipstream a Service Pack into your older XP CD (posted for comparison purposes only of course 
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