I have Windows XP Pro. I want to reformat. Does anyone have any good websites that will take me through a step by step process of this? I want to delete the current version of xp pro and put a new one on. I come to a menu where it says that there is already an operating system (my prior windows xp pro)and it says errors may occur installing another OS. Do I just proceed or do i have to do something else? Or does XP Pro delete the prior version automatically?