I have a MacBook Pro, 15", I'm running iOS 10.6.8. I purchased Mountain Lion through the App Store recently, but every time I try to update my Mac to Mountain Lion the installer never works. It will go through the process of "installing" it, and then it will restart my MacBook. Once it restarts, rather than rebooting into Mountain Lion it prompts me to accept the Terms of Agreement again. Once I accept the Terms of Agreement, it asks me to pick what kind of installation I want. (Backup, New copy of iOS, etc.) I pick install new copy of iOS, but whenever I do it will stop halfway and send me back to the Terms of Agreement screen. Whenever Mountain Lion first came out, my cousin bought it and tried to put it on my MacBook via his flash drive, but that never worked either. I'm thinking that may be conflicting with updating it through the App Store now.