pull down menus are transparent on websites

I am having graphics problems...regardless of which Internet browser I use (IE, Mozilla,) pull down menus on websites seem to be transparent. I can see text in these menus, but not back ground...very hard to use some websites because of this. All background shows thru pull down menus. In addition, it appears that most of the websites I use are pretty dull...no buttons show up, just text. Just seems like I am running at an abbreviated level with my web browsers here. Someone said maybe I have a problem with my Java? Means nothing to me. Can anyone offer any suggestions?