Start the Screen Saver in Code

To start the screensaver in code, you must send a message to the desktop window:

Declare Function GetDesktopWindow Lib "user32" () As Long
Public Declare Function SendMessage Lib "user32" _
Alias "SendMessageA" (ByVal hWnd As Long, ByVal _
wMsg As Long, ByVal wParam As Long, lParam As Any) As Long

Public Const WM_SYSCOMMAND As Long = &H112&
Public Const SC_SCREENSAVE As Long = &HF140&

Function gf_StartScreenSaver() As Boolean
Dim hWnd&
On Error Resume Next
hWnd& = GetDesktopWindow()
Call SendMessage(hWnd&, WM_SYSCOMMAND, SC_SCREENSAVE, 0&)
gf_StartScreenSaver = (Err.Number = 0)
End Function