Hello, I am beginning to think I repeated the same mistake of yesteryear when I upgraded from Leopard to Snow Leopard. Please keep in mind I'm not that technical but back then I installed it right over top of my existing OS as apposed to doing a clean instal. Anyway problems persisted until finally I wiped it all clean and installed a fresh copy. I was assured by Apple this wouldn't be the case with my new iMac and Mavericks but I am starting to see similar issues. The main issue are apps just locking up and not responding. Did most of you do a clean instal? Should I just bite the bullet and do the same? I did a full Time Machine back up over 300 gigs but I think if I use that I will get back the same corrupted OS correct? Any tips would be appreciated. Thanks!