You Need to Learn to Walk on the Rice Paper Without Tearing it
Try resetting the CMOS. Little button battery thingy, take it out wait 5 minutes, put it back.
Computers with restore discs instead of Windows installation discs, (a store bought copy of Windows) tend to be really tempermental about accepting anything other than the discs supplied with the machine. You will lose a lot of work on a "destructive"(full) restore, So the best thing to do is install your HDD in another computer, copy all your files, then go back to experimenting.
XP needs SATA drivers installed to complete an install. So, if you manage to get back into BIOS, set the HDD (s) to "run as IDE", that way XP will pick up the drives correctly.
I hope you've seen the old TV series "Kung Fu", otherwise the title may not make sense. Oh hell, who am I kidding, it may not make sense anyway.
BTW, there are still a few "eccentrics" around, such as myself, who actually still believe the XP is an Upgrade from Vista.