If you cannot install Windows XP, then it is likely a problem with your hardware. If you are using the 1003 revision BIOS with the Asus P4XP-X, then this will be the cause of your error. Asus only officially links to 1004 and 1005 on their website in the BIOS revision history. On their CPU compatibility list, no CPUs are shown to be compatible with the 1003 revision firmware. This can sometimes happen with very early editions of motherboards that aren't quite ready for release. Flashing the BIOS to 1004 or 1005 will fix this problem.
Instructions
1. Check the CPU Support List (see Resources). Check with which BIOS revision your CPU is compatible.
2. Navigate to the BIOS download page (see Resources).
3. Download the BIOS revision compatible with your CPU.
4. Double-click the zip archive. Select the BIOS file. Press "Ctrl"and "C." Insert your floppy disk. Click "Start," type "A:\" and press "Enter." Press "Ctrl"and "V" to paste the BIOS revision. Eject the floppy disk
5. Turn pm your Asus computer. Press "ALT"and "F2" during the startup to load the EX Flash program. Insert the floppy disk. Type in the BIOS name. This will either be "p4xpx004.awd" or "p4xpx005.awd." Press "Enter."
6. Press "Y" to update the BIOS and then "Y" to confirm. When the BIOS flash is finished, press "Y" again and then any key to reboot. Eject the floppy disk.
Tags: BIOS revision, floppy disk, 1003 revision, 1004 1005, compatible with, Eject floppy, Eject floppy disk