I'd like to preface this first by saying that I have used Macs for about five years and have troubleshooted a variety of issues by myself but this one is really strange. My girlfriend owns a mid 2009 unibody macbook that needed a ram upgrade and an OS upgrade. In February of this year, I purchased the correct ram and a snow leopard disk. I then installed the ram, verified that the ram worked(rebooted the computer with new ram, 4 gb) and went to install snow leopard. I popped in the Snow Leopard disc(the reason behind going to Snow Leopard is because she had a much older OS like Tiger or Leopard and the Mac App store did not exist for those OS's.) I started the clean install, went through the preliminary hoops and everything seemed to be working. About 30 minutes of a smooth process, the computer hung, installation stopped and after waiting 10-15 minutes further, I had to reboot the computer by using the power button. I restarted the computer and then everything got crazy. It would try to install snow leopard, but the installer kept hanging in the process. We tried it about 5 times and gave up. The girlfriend went to an Apple store and the "Genius" blamed the ram. So she bought a new computer a month later, and she asked if I could get her old data off the old computer(not much, most was backed up anyway.) So I just booted it up...and to my surprise, it asked me the basic new OS information...then booted directly into Snow Leopard...and it works fine. Great right? Wrong. I'm guessing that at some point, there were extra partitions made because the only available amount of hard drive space is 425 mbs...and she has a 250 gig hard drive in this computer...and the computer verified its a 250 gig hard drive...and it's a clean install! Or the OS defaulted for an 11gb partition? My question is mainly how do I figure out what else is on this hard drive? What is occupying space? Any utilities upon start up? Should I boot linux from a thumbdrive and figure it out there? I appreciate any feedback.