Windows wont boot?

[rohaninabout]

Hey everyone.

Having a bit of trouble booting.. was wondering if anyone could hint me towards it being a software or hardware problem.

Heres my story:
Up until today I've had a few wee things playing up, my CD drive dissapearing from My Computer etc. Had to restart to get it back. Then today I went on after leaving it running overnight and I had a system lockup (not a hard one, could still move mouse etc. Nothing was responding).
I couldnt even restart, so I did a cold restart. I noticed that it took a little more time to boot than usual. BIOS looked normal, and I got a reassuring beep. Then a big fat black screen saying "Reboot and Select proper boot device, or insert boot media in selected boot device and press a key".
Nothing like this has happened before, and I haven't changed anything.
I went into CMOS setup to check my boot device order, everything was normal. Hard drive was set 1st. It just said 'Hard Drive' though... not "Seagate blah blah blah". Maybe its not picking it up?
I wanted to check if it was my hard drive crapping out and I wanted to quickly get everything important off it, so I ran Ubuntu Live so I could quickly backup to disc. But it wouldnt even load the disc.
Then I tried doing a Windows recovering from the XP disc, which gave me an error aswell.


I've narrowed it down to being:

- Faulty HDD (maybe faulty SATA cable?)
- Faulty motherboard / RAM (would explain the slightly slower startups)
- BIOS corrupt somehow?
- MBR is screwed?

Does anyone have any ideas what else it could be or how I could fix it? I found some similar threads but they all had the boot devices priority wrong - I don't.
PS: Sorry about the wall of text! Just wanted to give as many details as I could so I can get as accurate feedback as possible.

Looking foward to replies, Thanks.

[rohaninabout]

UPDATE: Took it into the shop, it was a failing hard drive.

Bye 4 months of assignment work