direct x probloms

heyy my brother acserdently uninstalled direct x of off his computer and he doesn’t have internet on it at the moment so he cant download it agene so i download the install package for direct x 9.0 from my computer and installed it on his computer but his games steal wont work because of direct x so i installed a game that sed it would install direct x because the computer didn’t have it but t didn’t work so what can i do to fix it