Computer shuts down after new gpu install

[SpeedRacer87]

I just installed 3 things in my system. A brand new evga 850wb2 psu and a r9 290x Sapphire tri-x and a hyper 212 evo cpu cooler. Today I was having problems with the pc posting. I finally tracked it down to a bad ram slot. After I installed the new gpu as soon as I'm logged into Windows, the pc shuts down. I'm not sure what the problem is. Can someone please help me? I have tried to update the drivers but I'm not able to in safe mode.

Asus p8z77vlk
I5 3570k
R9 290x
Evga 850w psu

 

[SpeedRacer87]

I just removed the card and tried to boot the computer. The computer still shuts down while in Windows. This would mean the psu is bad right?

 

[SpeedRacer87]

I just hooked up my old power supply. I know my old psu is good but I'm still having the same problems. Could this ultimately be my motherboard?

 

[D_Perk]

Question for you. does windows try to boot up and then crash like you see the " wait while windows loads" or does it try to run but for like 3-5 seconds then shut off? Most of the time its the PSU but as you said you changed it back out and its having issues. i would guess it could be the mobo if it doesn't even make it to the loading widows part. if it makes it to windows and then crashes it could be your HD. but the mobo is the one that seems to be screaming out at the moment.