|Make sure you have installed the drivers for your sound card, if you do then try below.|
Try uninstalling and reinstalling volume control,but I recommend uninstalling and reinstalling multimedia altogether..
It is hidden by default in XP to unhide it you need to edit the Sysoc.inf file to view the Sysoc.inf file, you should enable the "Show Hidden Files and Folders" option under Files and Folders.Then Click My Computer.
Double-click C: drive.Double-click WINDOWS folder.Double-click the "Inf" folder and open the Sysoc.inf file with notepad.Locate the line.
"MultiM=ocgen.dll,OcEntry,multimed.inf,hide,7".Remove hide(leave the comma signs)
Save and close Sysoc.inf
Now go into addremove programs in the control panel,select addremove windows component,with Accessories and Utilities highlighted hit Details and uncheck multimedia or if you just want volume control..then highlight multimedia hit details and uncheck volume control then click ok and next and finish,now you can restart your computer.
Go into back into addremove windows component,with Accessories and Utilities highlighted hit Details and check multimedia or volume control..hit ok,next and finish and restart the system again.
That ought to do it.
Leadtek sucks BIG TIME