Alienware Aurora R4 randomly crashes.

Hey everyone.

After a long times search, with no answer to my problems, i have concluded that you are my last hope for this computer.

So, as the title tells you, my computer started crashing a while ago. When i say crashing i mean that the fan starts going to full power, then slows down, then goes to full power etc. etc.
And while this is happening my mouse and keyboard doesn't work either, yet my screen and sound keeps functioning as normal as ever, and the only thing i can do is to manually shut off the computer on the on/off button.

i have tried to update the BIOS to the newest version (in this case: Alienware A11) but unfortunately that haven't helped a bit. I have also tried Dell's diagnostics - which says everything is fine.

i have no idea what my next steps should be,
so i truly hope you guys have an solution to this problem. Thank you in advance.

Computer specs:
System-model       - Aurora-R4
Operating system - Windows 10 Home
BIOS                        - Alienware A11 (from 11-26-2013)
Processor               - Intel(R) Core(TM) i7-3820 CPU @ 3.60GHz, 3601 Mhz, 4 Cores
Graphic Card         - NVIDIA GeForce GTX 555

(ps. the crashing problems where there before i updated to Win 10)