Hello, I own a used MacBook Pro 15" (2007 model) that I bought last year. I didn't get the Mac OS X Install DVD with it, and either the Applications Install DVD. Anyways, My sister has also MacBook Pro 13" that she bought this year. She does have those 2 discs that I mentioned before, and I wonder if I can use them on my computer to format it? They both run the same Mac OS Leopard version. Although under "About This Mac" option on my MBP, it says 10.5.8, and on my sister DVD discs wrote "Mac OS version 10.5.7". Should it bothers me?