Graphics Card Issue

Hello guys, i am new here.

I'm having some troubles during my latest pc upgrade (low budget)

System Specs :

Motherboard: ASRock 960GM/U3/S3 FX
CPU: AMD FX 4300 3,8 GHz
RAM: 8 GB (4X2) CRUCIAL Ballistix Tactical Kit 1600MHz
PSU: TOP POWER PSU 650W
Video Card: Nvidia 9500 GT PCI-E 1024mb DDR2 HDMI DVI (The part i didn't upgrade)

Well after the installation my graphics card seems not working getting blacksreens in my monitor and doing nothing at all.With onboard graphics everything works well. Is it a compatibility problem because my mobo has PCI-E 2.0 and this card i'snt supported?

Or the mobo PCI-E 2.0 slot has problem ?

John