I moved this to its' own thread.
There are lots of possibilities for sound problems and the type of processor doesn't matter. What we need to know is the make/model of the motherboard, if it is a custom build, otherwise we need the computer make/model. Is this a new installation of W7? Was the sound working in W7 and then suddenly stopped?
If this is a new installation then you most likely need to get the sound drivers from the computer/MOBO manufacturer.
If it was working and suddenly stopped then try the Windows Fix-it for sound problems
And then there is always the possibility of hardware issues: jack plugged into wrong spot, damaged equipment, etc