This might end up being removed by admins because it's already a thread; however, there's a million replies to them and none of them are solutions so I'm hoping posting a new clean thread might generate some answers. ISSUE 1 - FREEZING ON BOOT UP Yosemite will freeze on the boot up screen; specifically it will load half way through the loading progress bar (Yosemite's replacement to the previous spinning wheel) and then freeze in it's spot. The only temporary fix to the issue is hold the PWR for 10 seconds and reboot it repeatedly until it decides to progress to the login screen, which cannot be good for the software with all of those improper shut downs. I have already tried resetting PRAM, Recovering from previous back up, Verifying and Repairing Disk Permissions - all to no success. ISSUE 2 - FREEZING ON SHUT DOWN Yosemite will freeze on shut down; specifically it will make it to the faded screen and spinning progress wheel to shut down ... but never actually shut down. I have already tried the same things mentioned above for the boot up freezing, and the only temporary solution I've found is to log out before shutting down. (1) this is annoying and Apple sells product for better features, (2) it doesn't even actually work every time doing that. Any solutions would be greatly appreciated and please do not post irrelevant information as I posted a new thread for a clean slate to hopefully get an answer out there because I know this is affecting a lot of people.