Un-installing usually isn't necessary.
Next time, save a copy of the conf in its original form somewhere so you can retrieve it and go back to the default settings in case things get screwed up.
If you want to change the game resolution, all you have to do is modify a few lines.
Here's mine. Only change the lines which show a *. Don't change anything else (and don't actually write in the *
)
[window]
*width=X
*height=Y
ColourBits=32
DepthBits=24
StencilBits=8
*ChangeScreenRes=1 (from 0)
FullScreen=1
DrawIfNotFocused=0
*EnableResize=0 (from 1)
EnableClose=1
*SaveAspect=0 (from 1)
Use3Renders=0
The main screens will still have the black areas, but the game itself will occupy the entire screen. Note that adjusting the resolution from the defaults generally results in a loss of frame-rates, so be sure everything runs well before you tune the graphics settings.
Hope you get up and running soon.