New to Apple...given this unit. New LW needs newer OS than mine. When I go to OLDAPPS, I go very deep, LW 4.10, and it still says my OSx 10.4.11 is too old. What is best way to get LW downloaded?

Processor 2GHz 2 Duo
Memory 1 GB667 MHz DDR2 SDRAM

Also, no matter what I do to find a "New Post" button, despite following the "New Thread" insructions. Where is the button? Thx