Const SM_CMOUSEBUTTONS = 43
Private Declare Function GetSystemMetrics Lib "user32" (ByVal nIndex As Long) As Long
Public Function CheckMouse() As Boolean
If GetSystemMetrics(SM_CMOUSEBUTTONS) > 0 Then
CheckMouse = True
Else
CheckMouse = False
End If
End Function
Private Sub Form_Load()
MsgBox "Проверка мыши на существование: " & CheckMouse
End Sub