Fort

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 screen appears again, follow 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 options such as caching or shadowing.
If you need to use safe mode to remove or disable components, restart your computer, press to select Advanced startup options, and then selest safe mode.
Technical information
***STOP: 0x000000ED. Что делать

tamalex

Читать это.

Отключите все устройства, подключенные в USB.
Проверьте шлейф на жестком диске.
Проверьте жесткий диск.

А вообще хотелось бы услышать, после чего это у вас случилось.