|You are not sure the CDR you are using has ever been successfully booted to. |
That would almost be necessary in order to install WinXP. You didn't upgrade from another operating system did you? WinXP was the only operating system ever installed on that computer?
Did you backup your personal files? Reinstalling would overwrite them and they would be lost.
Backup all personal files. Pretty much anything in My Documents. And if you kept music or pictures elsewhere be sure to copy them to CDR or DVDR if your burner is capable of writing to DVDR disks. Doesn't matter which. If you have an external hard drive you could copy stuff to it.
After you have copied absolutely everything you need to save then try opening some of those files to verify you made good copies.
Then we can work on performing a system restore or reinstalling WinXP completely.