I'm pretty new to Linux, and am having a hard time getting it to display right.

I've got Ubuntu 8.04, and nVidia GeForce 7600.

I'm running two screens at the moment, when I first installed Ubuntu, only one was running, so I installed the drivers using this method, http://ubuntuforums.org/showthread.php?p=6538071 (cb34's solution).

Now both screens are working, but my comp is running in low graphics mode.

I tried changing resolution by doing this

but it just went through some keyboard detection things, and eventually displayed "xserver-xorg postinst warning: overwriting possibly-customised configuration"

It's driving me nuts, can someone please help me?

sudo nvidia-settings
X Server Display Configuration -> Display -> Resolution

Hi, when I do that, it says "You do not appear to be using the NVIDIA X driver. Please edit X configuration file and restart X server", and the only options I'm given are enable tooltips, display status bar, and a couple of other unhelpful things.