I saw the Rendering Method Preference option in Call of Duty 2 that can be set to Direct X 7 or Direct X 9, with Direct X 9 I got like 15 fps on minimum settings and on Direct X 7 I had 30 fps with all maxed, so I want to ask if I can set Direct X 7 to other games too.Thanks in Advance.
Only if the game comes with that option. DX7 support has been dropped some time ago. Oblivion marked the death of DX8 back in 2005 since it was the first game to drop support for DX8.1. I would guess that DX7 support ended in 2003 or 2004.