IsAvailable Example for Visual Basic
'check the status of TWAIN
Dim RasterTwain As New LEADRasterTwain
Dim bTwn As Boolean
bTwn = RasterTwain.IsAvailable (Me.hWnd)
If bTwn Then
MsgBox "Twain is installed"
Else
MsgBox "Twain is not installed"
End If