some computers store windows on a partition on the harddrive and to access this you have to press a button or a combo of buttons during boot to enter the system restore. I personally hate when they do this because then you doon't get a windows disk. I think it's nice when you have both options. As for wiping out the drive, that's what I would do but make sure you have a full version of windows on disk before you format, especially if you're going to join the partitions. 70gb is not a lot of space. I have 128gb and 250gb on my other machine plus a 2tb NAS and I am always low on space. teehee, the life of a geekchick...