If you downloaded the new COD5 patch and don't have any sound this is how you fix it..(16bit DVD quality-Do this and you can still play cod5 and do other stuff aswell.. I figured this out)
(Doing this you must repeat and undo this change everytime you don't want to play cod5 or when you do)
Method A:
Right-click on the Volume icon in the taskbar (next to the clock, looks like a speaker)
Select 'Playback Devices'
Right-click on your preferred playback device (i.e. Speakers, Headphones, etc.)
Select 'Properties', then click the 'Advanced' tab
Set the Default Format here to '16bit,44100Hz(CD Quality)'
Note: You may reach the same menu in Method A through Control Panel > Sound.
Method B - Advanced users only (perform at your own risk:
Right-click on My Computer and select 'Manage'
Select Device Manager and expand 'Sound, video, and games controllers'
Uninstall listed Audio Drivers then reboot the computer
Vista will now auto-reinstall the on-board sound
Default Format is now set to '16bit,44100Hz(CD Quality)' automatically
Please note that setting your audio quality to 16-bit will not impact your Call of Duty: World at War gaming experience.
The game will sound just as good as it did before, as our sounds are mixed at 16-bit.
For those who need the patch you can download it from here
http://www.bigdownload.com/about/age-gate/?destination=http%3A%2F%2Fwww.bigdownload.com%2Fgames%2Fcall-of-duty-world-at-war%2Fpc%2Fcall-of-duty-world-at-war-v12-patch