Hello, I am way in over my head. I don't really know what happened except it seems it started after a Clean My Mac session, during which I was prompted every 4 seconds to install some kind of LIPO program (the command is required, etc). I read on the internet it was a Apple software so I didn't think too much about it and proceeded. After that, all hell seemed to break lose on the OS. First I noticed that Mail wasn't working correctly. It opens fine, and shows my list of mails. However, the preview panel states that No Message Selected, and when I double click a message, I get a grey screen and then the app crashes. I tried to look for a solution, which led me to needing the Terminal app. And then I noticed it was not launching. At all. No message. I bounces not even once before disappearing. This lead me to more research, and to the App Store. Same problem, the App Store doesn't launch. It sort of bounces before closing right away. And Photobooth doesn't work either. I'm getting a bit freaked out this, I have 0 clue what is wrong (the Lipo thing could have messed up everything) and how to fix it During my Clean My Mac session, I noticed it cleaned a lot from the Language section, not sure if related or not. iTunes works fine, same as Google Chrome, Safari. Please, please, help ! Oh and to spice up the challenge, I do not have the recovery CDs with me as I'm away from home (but if necessary I can get them later). Thank you to anyone that tries, it's greatly appreciated !