After I reformatted my hard drive i cannot get fallout 3 to play in my native 1440 x 900 resolution. The option simply isn't there in the fallout 3 launcher options. I was able to play fine before I reformatted may hard drive. I am using a Nvidia GeForce 9500GT.

Is there a check box "Show other resolutions" or something to that effect in the launcher? That should let you pick the other resolutions.

Otherwise, you can enter these values into the, I think it is called the Prefs file, or it might be the INI. I am not at my gaming machine, but a look at both of those files will show you which one to put it in.

I figured it out all i had to do was go to the moniter tab in the advanced window of my display settings and check show all resolutions and then it reappeared in my options menu.

You should really load your monitor's inf driver, so that you don't set it to a resolution (color depth and refresh rate) that isn't properly supported. Fallout 3 gathers available resolutions from Windows. The PNP inf driver usually doesn't have widescreen resolutions (as acceptable), although the version of Windows may change this.