ClickMonitorDDC is a useful free program that allows you to set the monitor brightness and contrast and the speaker volume through different, easy ways.
You can increase or decrease the brightness, for example, by rotating your mouse wheel over the program icon on the Windows notification area or by clicking on the button numbers or, still, by dragging the progression bar on the main window.
Unfortunately, the contrast can’t be set on a laptop display and I must say that I didn’t get it to work on my old external monitor connected through a VGA cable. Still, I find ClickMonitorDDC quite handy and, besides, it doesn’t require installation.
Right click the program icon in the Windows notification area to access the settings window. Here, among other things, you can disable the contrast icon.
You can download the zip file containing the program by visiting the following page: http://clickmonitorddc.bplaced.net