PC turns on, but the screen never comes up
Whenever I try to turn my PC, it turns on correctly, the ventilator spins and all that stuff. But the hard drive activity light doesn't turn on and the screen never comes up. I determined a few things:
The problem isn't on the power supply, because it would never turn on otherwise.
I think the problem isn't in the hard drive, because if the hard drive went bad, the BIOS screen should come up to then boot to whatever it boots to when the hard drive doesn't work.
So I think the problem is on the BIOS chip or on the CMOS battery (which seems unlikely, considering the BIOS screen doesn't come up)
I am not interested on the computer itself, cause I was planning to get a new one anyway.
But I am only interested on the hard drive's contents, cause there are some pretty valuable stuff on there, specially in partition "D:" , where I have a lot of OSes and stuff. I am 16 and I have no experience on disassembling computers whatsoever. What should I do?