Reza this is AsRock Support > AsRock P4I45GV motherboard > Downloads,http://www.asrock.com/mb/download.asp?Model=P4i45GV%20R5.0
(P4 i 45GV )
Choose which Operating System you are using. I'm going to choose Windows XP as an example,http://www.asrock.com/mb/download.asp?Model=P4i45GV%20R5.0&o=XP
The audio driver is a C-Media Audio Driver ver:UDA041_build04L
Under the heading to the right - Download From, click on the country nearest yours.
A small window will come up on the right -
Click on Save File.
Another small window will come up on the left.
At the top of this window tells you where the file will download to.
It may have Desktop, or My Documents, or Downloads, in the wording.
Desktop: The file will be on your desktop screen
My Documents: Click on Start, then on My Documents
Downloads: Click on Start, then on My Documents. DOUBLE-click on Downloads.
When you see the file name, ( C-Media_XP_2K_ME_98(UDA...., next to a yellow folder icon with a zipper on it), DOUBLE-click right on it.
On the Left side under the heading - Folder Tasks, click on Extract all files.
Now click on Next, Next, and Finish, at the bottom of the windows.
After you have clicked on Finish, close all windows. Go back to your desktop screen. Restart your computer. (Start > Turn Off Computer > Restart)
For additional questions please post in a Comment.