PC Shutting Itself Down

[ishraq2626]

I was just browsing and doing some calculations when all of a sudden everything started to close down and the Pc shut down.

Is this a problem?

My specs:

Intel Core i5 4690k
Asus Z97 Pro Gamer
MSI Gtx 970 Gaming 4G
Cooler Master 212x
G.Skill Ripjaws (4x2) 
Cooler Master V550w 80+Gold
Samsung 850 Evo 256GB SSD
1TB WD Blue HDD
500GB Hitachi HDD(Old)
Cooler Master 912 Haf

 

And everything is at stock settings,no overclock has been done.

Yes i know this is the second time im posting this,please tell me how to delete my last post.

TIA

[UnlimitedTMD]

I´m not good at this kind of stuff, but it may be your old HDD, not sure though, not good at it