i have win xp built into my hdd, how can i make a working os cd from it
You can slipstream your system with the latest Service Pack,which is #3, and your drivers using NLite and the excellent advice of Paul Thurrot at his site http://www.winsupersite.com. In case he doesn't mention it, you need ISOBuster to pull the necessary bootable ISO from your system so you can burn that to the CD.
Should have added that you can't, of course, use it on more than one system - M$ activation would be required on a new installation and it would fail the second time without a good hardware based excuse.
The link goes to his main site. But are you talking about the Slipstreaming XP item?
Note you need:
This time around, I'm only providing one set of instructions, involving only freely available tools you can readily find online. Here's what you need to make it work.
A Windows XP Home or Professional with SP2 Setup CD. It's possible that an original XP Setup CD or an XP with SP1 Setup CD will work, but I've only tested XP with SP2, both retail and volume license versions of the CD. (You may have luck with OEM CDs from PC makers as well, depending how much the company changed the disc layout.) Full or Upgrade CDs work just fine. Previously splipstreamed discs are fine as well. But I've only tested this with versions of XP that include just a single Setup CD: Media Center and Tablet PC users are out of luck.