Just letting everyone know that I found a way to reinstall the original sound card drivers in the Inspiron 8200, 2650, Latitude C840, Precision M50 (and others that have the same chipset) that were originally installed by Windows XP.
If you ever upgraded the drivers from Dell downloads and try uninstalling it, there's no way of gettting the older drivers back. What happens is that the file wdma_int.inf in the c:\windows\inf\ hidden directory is deleted upon upgrading the newer drivers. Here is the appropriate fix.
Here's the Dell|talk Forum thread:
**Remember: Proceed with caution. Laptopvideo2go.com is not responsible for any damage caused to your windows installation**
Download the zip File below and extract the files into your C:\Windows\INF folder and let Windows redetect your sound card: