With 'big name' PCs like Gateway, Sony, Packard Bell, etc,, the correct drivers are usually only available from their respective websites since in most cases the drivers are modifiied to match the (often) modified components. This means that regular drivers from other sources often won't work.
Go to the web-page I've linked to below, enter your system's serial number (0031531496) and click "GO" on the right of the serial number box.
http://support.gateway.com/support/drivers/dlcenter.asp