I am having an issue trying to insert a GeForce GT640 graphics card to my PC (The Motherboard is an ASRock H61M/U3S3), but BIOS or DEVICE MANAGER does not recognize the card.
I tried card in another PC and it worked fine.

My PC configuration is :

Motherboard : H61M/U3S3
Ram : 8GB
Bois : 2.20
Win7 64Bit

Any comments would be greatly appreciated.