Hi Mohy,
The latest Audio driver available for this model is Windows XP driver. Since this is the latest available driver in the Dell website, I would suggest
you to download this driver and install it in Windows 7 Compatibility mode. Here is a link to download the driver:
http://www.dell.com/support/drivers/us/en/04/Product/latitude-d610
Refer to this article for more information on program compatibility:
http://windows.microsoft.com/en-in/windows7/make-older-programs-run-in-this-version-of-windows
Hope you find this helpful. Feel free to get back to us if you have any Windows related queries in the future; we’d be happy to help.