Just for your information, you may have to press the Delete instead of F8 to enter Bios. (to change the boot order).
Some of the older machines did not use F8, if you will tell me the make and model I will try to find out which key is used to enter set up.
You are trying to do things the proper way so Wannabe1's advice to instal an OEM version of XP home is your best choice, once you can change the boot order.