Dell Windows XP defaulting to a color quality of 4 bit on Start up

Last night my Dell XP began defaulting to a color quality of 4bit on start up and I cannot change it. One time I was able to change it but it changed the sizes of my icons on desktop and make font smaller. About 5 minutes later I got the Blue Screen of Death, which i’ve been getting quite regular lately. Help! I dont know what to do to fix the color quality nor do I have any idea what is wrong.