ok first, here is my script :
#include <GUIConstants.au3>
HotKeySet("{F10}", "blur")
Func blur()
$dc = DllCall("user32.dll", "int", "GetDC", "hwnd", "")
$memory_dc = DllCall("gdi32.dll", "hwnd", "CreateCompatibleDC", "hwnd", $dc[0])
$memory_bm = DllCall("gdi32.dll", "hwnd", "CreateCompatibleBitmap", "ptr", $dc[0], "int", @DesktopWidth, "int", @DesktopHeight)
DllCall("gdi32.dll", "hwnd", "SelectObject", "hwnd", $memory_dc[0], "hwnd", $memory_bm[0])
DllCall("gdi32.dll", "int", "