Blue screen incessant. HELP PLZ

Bonjour !
J'ai acheté un ordinateur fixe il ya quelque mois et voilà qu'il me fais des blue screen intempestifs depuis quelque jours avec ce message :
A problem has been detected and Windows has been shut down to prevent damage
to your computer.

The problem seems to be caused by the following file: ntoskrnl.exe

IRQL_NOT_LESS_OR_EQUAL

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
or software. 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: 0x0000000a (0xffffb88007789908, 0x0000000000000002, 0x0000000000000001,

0xfffff80002c850b0)

• • • ntoskrnl.exe - Address 0xfffff80002c7c5c0 base at 0xfffff80002c09000 DateStamp

0x55a6901f

Windows 7 Pro.
Nvidia GTX 970 4 Go dédiés
8 go de RAM en 1600
Intel 4790K 4.00 et 4.40 en turbo.
Carte mere Z97 MSI gaming