It sounds like your hard drive has failed or the power feed to it has been interrupted somehow, perhaps a loose cable connector.
Laptops are a pain to work on and they usually use ultra-fine cables, often made specifically for a certain manufacturer or model of machine.
If you have a floppy drive available you could try to boot from a Windows startup disk just to see if you can read the directory structure of the C: drive. That would at least confirm whether the drive was activating at all and if so, whether its contents may be accessed at a lower level than Windows. Booting into BIOS could also let you see whether a hard drive is detected and configured.
I can't help but suspect the worst and, if you're lucky, a new hard drive is all that you'll need.