|Even if you made the CD correctly you still must hit any key to boot from the CD when you see that message on the screen. If you don't see that message then your CD was burned wrong. If you get no response from your keyboard when you attempt to hit any key then see the solution below.|
Sounds like you have TWO different problems. First of all, I don't know what you mean by "I created the WINXP boot disc using nLite slipstreaming the drivers". Your original CD was already bootable. All you needed to do was to add the SATA drivers and burn the disk.
What burning program did you use?
Second issue sounds like you are using a USB keyboard and Legusy USB devices is not enabled in the BIOS. This is a catch 22 situation. You need to change a BIOS setting but you can't get into the BIOS because of that setting.
The solution is to connect a PS/2 keyboard directly to the purple PS/2 port on the computer.