1) Open the file "c:\windows\wstream.ini" using Notepad or a similar editor. 

2) Toward the end of the file, look for a line which reads: 

     Driver=xxxxxxx

   and make sure it reads:

     Driver=cwbaudio.drv

3) That should fix the problem.  (It may be necessary to restart Windows.) 

The complete text of the file follows:

[WSMonitor]
Save on Exit=1
Auto Configuration=1
Number of Channels=16
Synthesizer Mode=1
Synthesizer Type=1
Enhanced Sound=1
Enhanced Stereo=256
Reverb Room=3
Reverb Volume=89
Polyphony=32
486Mode=0
MIDI Channel 0=1
MIDI Channel 1=0
MIDI Channel 2=0
MIDI Channel 3=0
MIDI Channel 4=0
MIDI Channel 5=0
MIDI Channel 6=0
MIDI Channel 7=0
MIDI Channel 8=0
MIDI Channel 9=1
MIDI Channel 10=0
MIDI Channel 11=0
MIDI Channel 12=0
MIDI Channel 13=0
MIDI Channel 14=0
MIDI Channel 15=0
Driver=cwbaudio.drv

[WaveStream]
LibraryPath=C:\WStream