Oblivion not working? Help please!?

I got Oblivion a year ago for my computer, tried installing it, it kept giving me error messages, so I gave up. Then today found this 'Oldblivion' thing thats supposed to change my settings to that they are as low as they will go, but I still get the error message and cannot choose to keep running executable or anything. Does anyone know of any mods or any way to set the settings as low as they will go?