Two things that I found useful this weekend when working on my Ubuntu Linux system. There are a lot of good Linux distributions to choose from; we use Debian at work, so Debian-based Ubuntu is a logical choice for home usage.
Disable Desktop Effects
If you turn on Desktop Effects and your hardware doesn’t support it, you can end up with an unreadable display. Even power-cycling and rebooting won’t help.
The easiest way to fix this is to switch to another console (ctl-alt-f4, for example), login, and run the following command, which removes the desktop-effects package:
sudo apt-get remove --purge compiz-core desktop-effects
More information and discussion is available at ubuntuforums.
Change Resolution
The typical way to change screen resolution is to click “System->Preferences->Screen Resolution” and select the desired setting. If the resolution you want isn’t available, you need to reconfigure your X server.
Begin by exiting X windows (by stopping gdm or kdm):
sudo /etc/init.d/gdm stop #(or kdm for KDE)
Reconfigure X; you may need to know your video card’s specs as well as your monitor’s specs; these are usually available online.
sudo dpkg-reconfigure xserver-xorg
To start Gnome/KDE again:
sudo /etc/init.d/gdm start #(or kdm for KDE)
More information and discussion is available at ubuntuforums.