Problem on Tombstoner's Laptop

[Mechanic]

Tombstoner is sort of busy now, so as his brother he told me to fill in for him to get help with his computer.

He started the computer and he has Ubuntu as well as Windows XP, so he chose Windows XP. Then it loaded for a REALLY long time and it said after on a blue screen of death that a problem had occurred, so it would restart. After that is said:

UNMOUNTABLE_BOOT_VOLUME

Then, it said about if it was the first time it happened, restart the computer, etc. At the end of the message, it read:

*** STOP: 0x000000ED (0x86577A68, 0xC0000185, 0x00000000, 0x00000000)

He was confused, so he tried Safe Mode, but it only typed a bunch of commands and froze. He restarted again and tried Linux Ubuntu. It loaded for about 8 minutes and went black.

Please help as soon as possible!

[Sherkel]

Thanks, Mechanic.
A few more details:
Start Windows normally causes a BSOD after the Windows logo. Don't restart after system failure is needed to read it.
Safe Mode causes a bunch of system file names to be listed, and then nothing happens.
Starting on Ubuntu causes it to stay on the black screen with the gray underscore flashing after displaying the things when it starts up. Stuff can be typed in, and Enter makes a line break, but nothing happens.

[IIMarckus]

Before you do anything else, get a LiveCD and back up any important data to a flash drive or external disk.

[Wack0]

unmountable_boot_volume ..
The partition's kaput.
Use data recovery software to get as much as you can off that partition as possible.

[Sherkel]

I'm just getting around to burning the LiveCD. Thanks.