Do you have a bootable cd? Doesn't matter what it is, we simply want to see if PC will boot from a cd.
If it does, "borked windows installation" to quote MechKB2
If not then we need to keep looking.
If you need a bootable cd then download Puppy Linux as an iso and burn it to a cd. If it boots from this we can copy your user files to a usb stick before doing any thing else.