No sound from speakers in new computer build

[mykanos]

Hi, I have a new build that I'm trying to troubleshoot. I'm not getting any sound from the speakers. I know they work because I plugged them into my laptop.

My hardware consists of:
Intel i5-750
Gigabyte ud-4p Motherboard
Corsair XMS 4gb memory
Lite-on Blu-ray drive
Samsung 1tb HD
MSI 260gtx OC3 graphics card
Corsair 850tx p/s
Cooler Master HAF 932
Logitech X-540 5 speaker setup w/ subwoofer

The case has a cable labled HD sound & a cable labled AC 97. I plugged the HD sound cable into the motherboard. I am not getting sound from the headphone jack. Nor am I getting any sound from the speakers! Is this a driver problem, possibly, or just a wiring issue? I hope it's not a defective part.

 

[r_manic]

Check first if your mobo's onboard audio is enabled (this is most likely done through your BIOS) or if sound is enabled on Windows. If neither fix the problem, recheck how you installed the components inside your computer.