I have a laptop that's having some is problems with windows 7 tried everything but can't get it to come up with out have the original cd this is where Ubuntu comes in I'm making the switch but I want to know since I will be booting from the cd or USB and installing it on the computer what about the old data that was originally on the hard drive will it be over written (this is what I want) or will have have to wipe the hard drive and then install Ubuntu?