Bill,
Sort of depends on the video card you have and what tools have been installed, but on Windows, under the Display settings tool, there is an advanced settings button that brings up the available tools to adjust your monitor. I use an NVidia card that includes it's own settings stuff (this under Linux), but usually, video card makers integrate their tools under the Windows Display tool's advanced settings (if you use Winders). Right click on the screen and select properties to see what you have.