Unfortunately none of the info in your post tells us either the make/model of motherboard, or the make/model of your PC. We need to know one or the other in order to source the correct sound driver.
As you have a Dell printer and a Dell monitor, I'm wildly guessing you also have a Dell PC which seems logical to me at least. If that's the case, Dell themselves host all the drivers on their support website. You'll need to know the model name and number:
http://support.euro.dell.com/support...s=dhs& ~ck=mn