Hi Folks, am new to Macs. Have a question about Macs. If I get a used MBP (was new in June 2011) where the 750 GB HD has been 'wiped', will I be able to install/load any particular version of MAC OS X on it? It originally had SL 10.6.X on it and owner lost the orig SL disk. Not being familiar with how Apple does things, can I just purchase a DVD or USB of say Lion and do an Install or is there some kind of restriction that would prevent me from doing that? Would I be restricted to loading ONLY the previous version of SL on it?