From the snippet: https://www.autoitscript.com/wiki/Snippets_(_GUI_)#Center_Window_on_Screen #include <GUIConstantsEx.au3> Global Const $GUI = GUICreate("Test Window",300 ,300 ,100 ,100) GUISetState(@SW_SHOWNORMAL) Sleep(2000) _Middle($GUI, "Test Window") While 1 Switch GUIGetMsg() Case $GUI_EVENT_CLOSE ExitLoop EndSwitch WEnd Func _Middle(Const $win, Const $txt) Local Const $size = WinGetClientSize($win, $txt) Local Const $y = (@DesktopHeight / 2) - ($size[1] / 2)