The basic window-creation function is WinCreateWindow. This function uses information about a window's class, style, size, and position to create a new window. All other window-creation functions, such as WinCreateStdWindow and WinCreateDlg, supply some of this information by default and create windows of a specific class or style.

Although the WinCreateWindow function provides the most direct means of creating a window, most applications do not use it. Instead, they often use the WinCreateStdWindow function to create a main window and the WinDlgBox or WinCreateDlg functions to create dialog windows.

The WinCreateMenu, WinLoadMenu, WinLoadDlg, WinMessageBox, and WinCreateFrameControls functions also create windows. Each of these functions substitutes for one or more required calls to WinCreateWindow to create a given window. For example, an application can create a frame window, one or more control windows, and a client window in a single call to WinCreateStdWindow.