Can't change laptop screen brightness with Function key

[theanimala]

I have a preowned Compaq Armada M700 laptop with a 14.1" TFT display. It seems as thought be brightness is way too high and colors are washed out. The function + F10 key does not do anything (nor the function + any key for that matter). Is there something I need to download to enable these functions or is there some other way to do this?