This was an error I found on my computer that I did a search on the web for a quick and easy fix for. I found this forum that had my error and symptoms, but found no one had a solution. The thread was closed because the original poster had not responded to the posts in over a year, even though it sparked a lively discussion with others saying they had same problem (at which Daniweb admins kept scoffing! I say LET THEM POST! Even if they don't have an answer, knowing that others have the same issue and finding out how it was caused in each case can be very good and help toward a solution!). I thought that was @$$ and was what made me join this forum, to give those having this problem the answer they deserved and not the closed thread they got in return. Whataloadacrap.
Background: This error occurs after trying to uninstall the updated (and overrated) C-Media WDM Audio Driver for onboard sound that appears after upgrading to XP SP2 and/or going to WindowsUpdate. Likely the driver didn't work, so you tried uninstalling the driver and were going to put back the old Realtek AC'97 driver, but couldn't get rid of the updated driver.
To fix: Start, Run, type in "regedit" (no quotes), and delete the cmaudio string from
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run. This makes it so it will not run on startup and try to find the cpl file that was deleted during the uninstall or not installed correctly by the installer in the first place, whichever your case depending on when you started seeing the error. If your sound was working perfectly before this, you are done. To get your sound working again if it isn't, read on -
While still in the registry editor, click on the top computer icon in the Registry Editor to highlight it (so that it will do a complete search of the registry and not just from your present point forward), do a Find (Ctrl+F) and find and delete all KEYS related to cmaudio and C-Media, not just the string entries, but the KEYS, except for that entry in the Run key I mentioned above, just delete the cmaudio string for that one.
Delete the string "CMCPlus" from HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Control Panel\Cpls to get rid of the Control Panel icon, and delete the file it points to that resides in C:\Windows\System32.
Download this remove utility from
http://ekiis.com/Freesoft/binary/remove11.zip
and run the file you find in the zip file - it can be ran without extracting it from the zip. Take out the C-Media Audio Driver line.
-- NOTE: This utility is for taking the name out of the Add/Remove Programs section only, and does not remove it from your computer, but it is very useful for issues like this when we are MANUALLY uninstalling a program to take it out of the Programs list and should work in 98/ME/2000/XP.
Delete these files from the C:\Windows\System32 directory (or "System" directory for Win98)
cmirmdrv.exe
cmirmdrv.dll
cmuda.dll
Delete everything you can readily delete in C:\Temp, C:\WINDOWS\prefetch (XP only), C:\WINDOWS\Temp, and C:\Documents and Settings\%YourName%\Local Settings\Temp (2000 and XP only), so that there will not be any files left for it to try to recover the driver from. You will likely have to leave things that start with hsperfdata_ and Perflib_Perfdata_***.dat files if you find them, but should be able to delete most others without changing attributes.
Now open the Device Manager (Right-click "My Computer", hit "Manage", then find Device Manager in the Computer Management console). Right-click the C-Media WDM driver under Sound, video, and game controllers, hit Uninstall. Then right-click the top computer icon listed there with your hostname beside it, hit "Scan for hardware changes". It should install a generic "Multimedia Audio Controller" instead of the "C-Media WDM Audio Driver", though you might see that C-Media Audio for just an instant before it reverts back to a generic driver (if it stays, you'll have to go back through the registry again, delete the system files again, and do a full search of your hard drive for those files so they don't get re-copied again). From here you can download your specific Realtek AC'97 Audio Driver setup.exe file here or use your motherboard's installation CD to re-install and you should have sound again.
Good luck.