Sound card installin problem

I am facing problem with sound card installation as my on board sound is not functioning and whenever i install the sound card it get installed but after rebooting it does not function so i thought it must be a motherboard prob i ordered a new intel chip set motherboard and installed and then onboard sound was working but i was finding the volume little low so i tried to install sound card on the new one but again the same thing is happening, so kindly guide me as wats the actual problem is there with sound, thanks and obliged.