Help BSOD issues!

greetings

recently my dad decided to install a discrete gpu into his system but ever since then his pc started to act up. it would randomly shut down and restart, disturbing his works and stuff. but heres the real problem: the pc would pass the POST but never be able to load windows. this usually happens when the system gets the BSOD for only god knows why.

I cease to believe that the newly installed GPU is the issue because it definitely worked perfectly for a few days and has never failed in delivering such good gaming experience. However i feel that the HDD has got something to do with this. So the question is what should i do to diagnose the main issue of the pc? please note that the pc is about 5 years old. The specs are as follows

  • Intel® Pentium® Processor E2200 
  • (1M Cache, 2.20 GHz, 800 MHz FSB)
  • Asus P5KPL-AM motherboard
  • 160gb HDD
  • 550w headway PSU
  • Samsung 22x dvd drive

So what should i do exactly? any suggestions would be appreciated

 

-dan

 

points to note: buying a new rig is not an option, i did not overclock the cpu

I

@leenucks ive tried doind that but my pc reboots again when i attemp to install the OS and sometimes it brings me to a Red Screen of death during the installation.