Two desktop environments are available on the linux systems: KDE and GNOME. The default is KDE. To switch desktop environments you must be logged out and at the hellolinux login screen. Click Options and then Select Session...
If you want to change your screen resolution from the system default, you can use the screen resize and rotate utility, under the system tools KDE menu.
There is also a KDE tray tool that can be started by typing
krandrtray in a xterm window.
To change the screen resolution from the default, use the Screen Resolution tool under the Preferences GNOME Applications menu.
From the command line, you can use the