Use the games configuration settings and apply the new resolution settings
you choose. If the game has a full screen option also use it. If they are
indeed that old and won't work correctly then right click on the shortcut you
use to activate the game and then click the compatability tab and then choose
the OS that the system was designed to run on. Also check the site of the
game manufacturer or distributor for any updates and patches. Some updates
make the game more compatable with XP.