Minimize All Windows

'Add a module to your project (In the menu choose Project -> Add Module, Then click Open)
'Add 1 Command Button to your form.
'Insert this code to the module :

Declare Sub keybd_event Lib "user32" (ByVal bVk As Byte, ByVal bScan As Byte, _
ByVal dwFlags As Long, ByVal dwExtraInfo As Long)
Public Const VK_LWIN = &H5B
Public Const KEYEVENTF_KEYUP = &H2

'Insert this code to your form:

Private Sub Command1_Click()
Call keybd_event(VK_LWIN, 0, 0, 0)
Call keybd_event(&H4D, 0, 0, 0)
Call keybd_event(VK_LWIN, 0, KEYEVENTF_KEYUP, 0)
End Sub