I assume you tried to activate the volume control for the system tray in taskbar and got that message? This is a pretty common problem then. In some cases, the Sndvol32.exe application (the mixer) doesn't install. Provided you I got you right and you tried to use the old soundcard again and there are no conflicts reported in the hardware manager, here's my suggestion:

Try a search for this Sndvol32.exe file on the disk. Last time I missed it I found it in <Windowspath>\System32\dllcache. Or just copy it from your other computer. Put it into <Windowspath>\System32. Then go to control panel -> "sounds and audio devices" and try to check "place volume in task bar" again. If this doesn't help, please describe the problem again more detailed, i.e. if you have any sound at all or if there are hardware conflicts.