Private Declare Function GetSystemMetrics Lib "User32" (ByVal index As Long) As Long
Private Const SM_CMOUSEBUTTONS = 43
Private Const SM_MOUSEPRESENT = 19
Dim X As Long, Y As Long
Dim S As String

Private Sub Command1_Click()
X = GetSystemMetrics(SM_MOUSEPRESENT)
If X = 1 Then
Y = GetSystemMetrics(SM_CMOUSEBUTTONS)
S = "Mouse present " & vbCrLf
S = S & "and it has " & CStr(Y) & " buttons"
MsgBox S, vbExclamation, "Mouse"
Else
MsgBox "Attention! Mouse is not present", vbCritical, "Mouse"
End If
End Sub