I am pretty sure disabling the sound card would be a bad thing, it is heading towards making a virus. If you mean muting the volume, use the waveOutSetVolume:
Code:
Public Declare Function waveOutSetVolume Lib "coredll.dll" (ByVal device As IntPtr, ByVal volume As Integer) As Integer
(taken from PInvoke.net)
Where the volume is a bundle of two shorts, which can also be seen as this:
Code:
Public Structure volume
Public left As Short
Public right As Short
End Structure
Public Declare Function waveOutSetVolume Lib "coredll.dll" (ByVal device As IntPtr, ByVal volume As volume) As Integer
Code:
Dim rval As Integer = waveOutSetVolume(0, 0)
Mutes the volume.
For enabling/disabling take a look at this post (in c++)
http://stackoverflow.com/questions/1...disable-device