EnableBlur(gHwnd)
{
    ; WindowCompositionAttribute
    WCA_ACCENT_POLICY := 19
    ; AccentState
    ACCENT_DISABLED := 0
    ACCENT_ENABLE_GRADIENT := 1
    ACCENT_ENABLE_TRANSPARENTGRADIENT := 2
    ACCENT_ENABLE_BLURBEHIND := 3
    ACCENT_INVALID_STATE := 4
	
    accentStructSize := VarSetCapacity(AccentPolicy, 4*4, 0)
    NumPut(ACCENT_ENABLE_BLURBEHIND, AccentPolicy, 0, "UInt")

    padding := A_PtrSize == 8 ? 4 : 0
    VarSetCapacity(WindowCompositionAttributeData, 4 + padding + A_PtrSize + 4 + padding)
    NumPut(WCA_ACCENT_POLICY, WindowCompositionAttributeData, 0, "UInt")
    NumPut(&AccentPolicy, WindowCompositionAttributeData, 4 + padding, "Ptr")
    NumPut(accentStructSize, WindowCompositionAttributeData, 4 + padding + A_PtrSize, "UInt")
    
      ;	DwmSetWindowAttribute https://docs.microsoft.com/ru-ru/windows/desktop/api/dwmapi/nf-dwmapi-dwmsetwindowattribute
    DllCall("SetWindowCompositionAttribute", "Ptr", gHwnd, "Ptr", &WindowCompositionAttributeData)
}


Gui +LastFound -Caption +Border +hwndgHwnd +AlwaysOnTop 
WinSet, TransParent, 254
Gui, Font, s33, Segoe UI
Gui, Add, Text,     Center cWhite, Hello Blur!
Gui, Add, Text,  Center cRed , Hello Blur!

Gui, Add, Button, -BackgroundTrans, Button 
Gui, Add, Text, wp Center -Background, Text
Gui, Add, Edit, wp Center -BackgroundTrans, Edit
Gui, Show,   Center
EnableBlur(gHwnd)


GuiEscape:
GuiClose:
Escape:: ExitApp