Installation\Manual X Setup
If you are not using a separate graphics card and a widescreen monitor, you may need to configure X yourself in order to get the correct resolution.
Run the following command using the resolution height, width and sync you want to use and note down the output.
$ cvt width height sync
Then edit /etc/X11/xorg.conf to appear similar to the below. The Modeline is what you generated with cvt just now. Note that all the quote marks are important. If this does not work and you have missed a quote mark, you can use SSH to nano the xorg.conf and reboot the server.
Section "Device" Identifier "Configured Video Device" EndSection Section "Monitor" Identifier "Configured Monitor" Modeline "1280x768_60.00" 79.50 1280 1344 1472 1664 768 771 781 798 -hsync +vsync Option "PreferredMode" "1280x768_60.00" EndSection Section "Screen" Identifier "Default Screen" Monitor "Configured Monitor" Device "Configured Video Device" DefaultDepth 24 SubSection "Display" Depth 24 Modes "1280x768" EndSubSection EndSection
Now reboot your computer or restart X to get the correct resolution.
There is a program you can use called xrandr to try out different resolutions, see this wiki page.