[This is a copy&paste from the main forum thread you posted. I guess it may be useful here too]

Some of the earlier Lego games lack a windowed mode option. Lego Indiana Jones has no option, and has no windowed functionality, while Lego Batman has no option, but has windowed functionality.

From what I know, if the following advice doesn't work then the game can't go into windowed mode.

Find the shortcut for the game, right click it, then click "Properties". Go to the "Shortcut" tab and find "Target" In the "Target" box, at the end and after the " marks type -windowed

This should force the game to open in windowed mode, if the functionality for it is available.

Quick update on the post above.

There is a program called DXWnd which can force most programs into forced windowed mode, including this and Lego Indiana Jones. If there's any confusion using it this tutorial should help.

Here's how to specifically run Lego Star Wars Saga in Windowed-Borderless mode:

:D