IE8 - how to reopen tabs in all windows after a restart?

If I open several windows of FF, with several tabs in each, only the last closed windows tab-set is opened the next time I open FF. However, IE8 lets me reopen last browser session. If I have a large tab-set that I wish to work on at a later point in time, I add the entire set to Favorites using "Add current tabs to Favorites", under it's own folder, and name the folder something relevant.. That way I'm sure to keep all my tabs for later... There's no limit to the number of Favorites your browser can handle.. ;o)