Nvidia 560gtx hardware conflict

[ScrollGuider]

Hello,
I've been facing a problem in regards to my new gtx 560 graphics card. when ever i try to install it and boot up my pc it will stay at my hp blue boot screen and go no further. However when i put back in my gtx 9600 it works fine. I'm not sure what it might be that wont allow my computer to go past boot when using my gtx 560 so any advice would be appreciated.

 

[abCasPeRR]

What is your power supply, could be related to that.

 

[ScrollGuider]

nope, i just recently upgraded to a 750 watt power supply. I also reset my bios too in hopes of successfully installing it.