The PC can't load a driver for the sound card. Is there any sound when you get into Windows? If there is then it's the DOS driver that's missing. I'd try re-installing the sound card drivers first.
If that doesn't work and it is the DOS driver, then you can probably disable the DOS sound profile. It will mean that you won't get any sound when using DOS though. Most programs run in Windows now anyway, so that probably won't be a problem.
If the sound card has been changed then the PC may be looking for the drivers for a card which isn't there, in that case you'll need to go to system properties and remove the old card if two are listed.