I had a difficult time finding a guide on how to do this, so I just tried to figure it out the best I could. I originally had a 320 gig standard drive called "Macintosh HD". I ordered one of those new 640 gig WD drives, and put it in slot 2. I went into Disk Utility, went to "restore", and put my 320 gig as the source drive and the new partition on the 640 (which I also named "Macintosh HD") as the destination, and clicked "restore". An hour or two goes by, and it says it's done. I turn off the mac, pull out the first drive (the 320) and it boots fine into the 640... I tested Mainstage, Safari, and basically everything seemed to be there. I changed the desktop background so I could tell them apart, put the 320 back in, and when I rebooted, it booted off the 320. This time I went into System Preferences and changed the startup disk (I guess at this point I should have named the partition something different) and it booted up on the new 640 again. I'd like to format the 320 but am terrified if I did this all correctly. I plan on using it for boot camp. None of the links I found suggested doing it this way, they all talked about third party utilities. Anyone here care to help me out? Can I go and format that new drive safely? Is there something I can do to preserve the data (just in case) but take away the boot capability?