crash My PC crashes but dont know why?

[SoulSage]

Problems Occurred ->                           Black Screen and stuck at it (Crashes a lot), programs not responding, Very slow 

Solutions tried ->                                   Updated BIOS, swapped HDD, GUP,SMPS all ware working fine, Changed new OS  (5 Times),Went to service center they said it was HDD problem bought new HDD WD 1TB worked for 4 days but back to same problems, used BIT DEFENSDER to scan for viruses in both in internal and extenal HDD shows no Problems, no beeps, no error msg, no abnormal programs, no background operation  None Worked

Programs run->                                      RIFT mmorpg, Photoshop and other basic simple programs.

Windows Version        ->                        Microsoft Windows 8.1 (6.3) Professional 64-bit   (Build 9600) 

 Monitor Mouse Keyboard ->                SMB2230 (Samsung)

Power ->                                                  iBall Mharathon 500W

CPU ->                                                     Intel(R) Core(TM) i5-2320 CPU @ 3.00GHz

Motherboard ->                                      Intel DH67BL

HDD ->                                                     Toshiba 1TB (now WD 1TB HDD as suggested by service Engineer  )

GPU ->                                                     ASUS Nvideia DDR3 2GB ( bought new Gigabyte DDR5 2GB GT730 as suggested by service mechanic)

RAM ->                                                     Kingston 2x 4GB DDR3 

The problems still occur now image files and normal programs not working and cant do any normal work only waste of money for the HDD which they wont take back,

Tried all that solutions i know and all the solutions given by the shop.

Pls tell mewhat is wrong with it is it my CPU or motherboard or any other ?

[Brooksie359]

Is that 8gb of ram total then?

[JohnDongus]

I would check windows error reporting, and then check tempatures 

[SoulSage]

11 hours ago, Brooksie359 said:

Is that 8gb of ram total then?

Yes totalk 8 GB RAM

[SoulSage]

11 hours ago, JohnDongus said:

I would check windows error reporting, and then check tempatures 

The temperature is fine I evan changed the heat sink paste but I can't get to windows error check won't launch and just now is completely crashed and tried repair and troubleshoot but can't fix it need to change is again to work and that to throws error when partion is created

[Brooksie359]

Could be a power issue. I know bad psus will can cause a crash. 

[JohnDongus]

9 hours ago, SoulSage said:

The temperature is fine I evan changed the heat sink paste but I can't get to windows error check won't launch and just now is completely crashed and tried repair and troubleshoot but can't fix it need to change is again to work and that to throws error when partion is created

Since you said you've reinstalled will does multiple times it has to be a hardware error, so maybe ram or something. Either that or you are downloading so ethics you shouldn't.