windows xp install gone bad

Keep hitting your delete key like a chicken eating scratch while booting,this should get you into the bios. check if you have a section called hardware monitor,go there and check your voltages. 12v,3v,and 5v should be close to spec. sounds like you have a power problem.

who installed the vid card? was there a extra wire attached to it,make sure it's attached.

could also be the IDE cable is not plugged in right,make sure all plugs in the case are secure.

you can also try hitting your insert key while booting,this will load default bios settings on boot.

before going into your case shut the power and hit the boot button once to expel any remaining power.