I need to completly clean everything on my computer, making it as though it is brand new. I have no Windows CD, so is there any way I can still do this? Thanks in advance.

if i put all my files on my documents , n then install windows xp againwith xp cd to clean would the files be save on documents and settings on the user folder after i install it ?? or would they be deleted to ????

Is there an easy way to restore my computer back to its original time? I want to start over, delete everything and have a more responsive computer.