Reverting from vista to xp

i have windows vista home basic and i want to revert back to windows xp pro . how can i do this ? when i try to load xp pro . it won't load and i get a blue screen with white text error messages that says i need to disable shadowing and caching and try switching video adapters . how do i disable caching and how do i switch video adapters ? any suggestions ? all comments are welecomed . thanks !!!