Help, Unmountable Boot Volume Win XP

Hi guys, a friend has a Toshiba Qosmio G25-Av513 with Windows XP media Center 2005. I was running fine on day, then the next day it will not boot up... I try to boot up the computer, and it will show the XP splash loading screen, but will stop about a min in to the boot with a error of Unmountable_Boot_Volume. I boot up in safe mode and it freezes at C:windows/blah blah blah/ System32/MUP.SYS. then go to the blue screen with white letters. I have tried to do a restore of windows, but they do not have the XP CD, so i tried the Dell XP for 2001, and it worked, but when the menu comes up on what to do, one is to install XP, Witch is Enter, then another one is "R" restore, then last is "Q" quit. i have tried both enter and R and it says that computer does not have a HD installed. I do not think it is the HD that came with the computer, it is only 60GB. What can i do to get windows up and running?

Tech numbers:
stop: 0X000000ED, 0X86780900, 0Xc00000815, 0X00000000, 0X00000000
thanks!

 

Can you get your hands on a Windows XP disc? It will allow you to replace most essential system files with a Repair feature.

 

spinrite often can help

 

Using a Dell restore CD on a Toshiba is not going to help you.

 

@OP: OEM restore discs are meant for specific models. Therefore, you cannot use a Dell restore disc on any other machine, as Rlynn said.

Like I said in my first post, you should be able to repair any broken system files by using the Repair function that comes with an ordinary XP disc. Maybe you can borrow an XP disc from a friend.

Or, if you are a college student, it would be handy to pay the discounted price to get a license from your college/university. That way you would have an XP CD to rely on in the future.