Ordi qui se bloque écran bleu

Bonjour tout le monde,

Voila j'ai un problème avec mon pc et je suis vraiment nul en informatique!
Mon pc bloque (je ne peux plus rien faire souris bloqué clavier aussi) et parfois affiche cet écran bleu:

A problem has been detected and windows has been shut down to prevent damage to your computer.
If this the first time you've seen this stop error screen,restart your computer.If this screen appears again, follow these steps:
Check to be sure you have adequate disk space. If a driver is identified in the stop message, disable the driver or check with the manufacturer for driver updates. Try changing video adapters.
Check with your hardware vendor for any BIOS updates. Disable BIOS memory options such as caching or shadowing. If you need to 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: 0*0000007E (0*FFFFFFFFC0000005, 0*FFFFF8000306A0DF, 0*FFFFFA60019D2168, 0*FFFFFA60019D1840)

Je ne sais pas quoi faire..... Au secours!!!