Porque me sale este error

[Manuel Lopez]

Cuando prendo la computadora y despues que pasa el logo de WINXP me sale en una pantalla azul este error:

A problem has been detected and windows has been shut down to prevent damage to your computer.
UNMOUNTABLE_BOOT_VOLUME
If this is the first time you've seen this stop error screen, restart your computer. If this screeb appears again, follor these steps:
Check to make sure any new hardware or software is properly installed. if this is a new installation, ask your hardware or software manufacturer for any windows updates you might need.
If problems continue, disable or remove any newly installed hardware or software. Disable BIOS Memory options such as caching or shadowing. If you need yo use Safe Mode to remove or disable components, restart your computer, press F8 to select Advanced Startup Options, and then Select Safe Mode.

Technical Information:
***STOP: 0X000000 EDC0X80F0DE30, 0XC0000125, 0X00000000, 0X00000000

Porque me pasara eso. Que significa ese problema Porque me sale. Ayudenme.