Recently, I purchased an black MacBook 2.16GHz running Lion. I installed Mountain Lion with MacPostFactor, and I'm not exactly happy with it. I'm having two big problems: 1. Speed + Fans Before I installed ML, I was using Lion for a bit. Lion was fast and the fans didn't come on a lot. After I installed ML, the OS seemed a bit slower (even though I heard it would be faster) and the fans are always on. The only time they turn off is if I leave the Mac sitting for 2 or 3 minutes with all apps closed (not an exaggeration!). Any tips on cooling down the Mac and making the OS speedier? EDIT: Turns out the fans were always on and the OS slow because Spotlight was indexing! It'd done now, and the fans are still on more than they were in Lion, but they aren't on all the time anymore. The speed is better too. Now iMessage is my main problem. 2. iMessage One of my top reasons for installing ML was iMessage. However, it doesn't let me sign in. I spent at least an hour on the phone with Apple about this, and after talking with this one person for a long time, I was directed to a hardware department that doesn't work with Apple ID or iMessage (LOL!). I did learn one thing with the first person though; my software is likely too old. Is there possibly a hack to get it working? Maybe use the Mavericks version of Messages? REAL help is much appreciated. I like ML, but if it continues to run the fans 100% of the time and iMessage, my top reason for upgrading, won't work, I may just go back to Lion. It ran better and without fans. Thanks.