I try not to be too techy, but here goes:
1. Make sure you have enable the system to boot from CD/DVD ROM 1st. To do this, you need to do some setting in BIOS. Observe the screen when you power up the PC where they mention something like "PRESS DEL TO ENTER BIOS" which is what you need to do (press the Delete key on your keyboard). In BIOS, look for the Tab named BOOT (use <- & -> key on keyboard to navigate), look for one option mentioning boot device priority, adjust the setting until the CD/DVD is place as 1st boot device (to do this, read the instructions text place at bottom screen). Once done, navigate to the last Tab and select Save the setting & restart the system, press enter.
2. Insert the XP installation CD into the CD/DVD ROM drive.
3. The Black screen appear with line of text "Press any key to boot from CD/DVD", press Enter.
4. Let the XP installation file load by itself. The process usually should be fine if there is no hardware damage.
5. When all files loaded, a simple intro screen appear, press Enter to proceed install XP.
6. A long list of agreement appear, just press F8 on keyboard to proceed.
7. 3 options available, press R on keyboard to select the Recovery Console.
8. Black DOS screen appear, when asked for which WINDOWS system to attend, press 1 on keyboard to select Drive C.
9. When ask for Administrator password, usually just press Enter on keyboard if you're sure no password assign before. Be careful as it only allows max 3 fail attempts, then you need to start the entire process again from step 3.
10. When the console is ready (C:/ ), type chkdsk to run a simple check disk process.
11. Once check disk is done, type fixboot as the console will generate a new startup file.
12. Just press the restart button on the CPU to reboot the system. Remember to remove the XP CD from the drive.