I am using Windows XP. On my system all images are displayed very dark. I tried googling around but douldn't find any specific issue. My monitor is working fine but still images are dark.
Those are for adjusting the brightness or contrast and other display related settings.
There are various methods in different monitors for browsing through them.
Just adjust the contrast and brightness to your desired settings by trial & error method.
Right-click on Desktop and select "Properties" and then click on "Settings" tab and then click on "Advanced" button! Here u'll find a tab which lets u set the GAMMA, Brightness, etc. for ur monitor. Just play around them or click on "Reset Defaults" button( If available).