GW_HWNDFIRST top-level constant
int
const GW_HWNDFIRST
The retrieved handle identifies the window of the same type that is highest in the Z order. If the specified window is a topmost window, the handle identifies a topmost window. If the specified window is a top-level window, the handle identifies a top-level window. If the specified window is a child window, the handle identifies a sibling window.
Implementation
const GW_HWNDFIRST = 0;