Okay so I have ML on my MBP here at University. I have ML but it's way too buggy and many applications dont work, including my scanner. I want to go back to SL or Lion. I have the original disc of SL and obviously purchased Lion from the Mac app store. Here's the situation though, that I dont want to lose anything on my 500GB internal HD. I'm utilizing 300GB's and can't lose anything considering my backup external HD is at home back with the folks; with no way of me being able to retrieve it till July. Wondering whats the best solution for this. Furthermore, I would hope I have the option of choosing either SL or Lion and not lose any of my data; hoping the decision is a matter of what I like; such as Spaces & Expose from SL, or iCloud and Photo Stream from Lion. Any help is appreciated.