I have been having some serious hang ups on my i5 iMac and I have no idea why! Clean system, don't download much, and I keep it very clean. Over the past month it hangs up randomly while working in Safari, iTunes, etc.... A couple times an hour. In any event, I know I just want to start fresh but I need my Videos, Pics, and Music. If you've read this thread by me, you know that I can't back up to my external. Can I partition my HDD for around 150GB and then do I a clean wipe of OSX, copy my files back to the clean install and then un-partition the drive?