I currently have a 2011 Macbook Air that my girlfriend would like to buy from me I intend on installing Mountain Lion for her so she has the latest OS on it but what would be the best option for doing this? I currently have $25 itunes credit that I used my Best Buy Rewardzone coupon to purchase with the intentions of using it to upgrade to ML (so technically I didn't spend any of my own money). So my question is what would happen if I were to purchase and download ML using my Apple ID and then wipe the computer for her to use her Apple ID and still have Mountain Lion? My biggest concern would be if it ever needs to be "reformatted" would we need to buy it again using her Apple ID? Also is this even legal? Finally on a slightly different note is it legal to rip the OS X mountain lion image to put it on my own USB as a recovery option? I know it is a lot of questions for a fairly simple question but I intend on buying the new 2012 Air that will have a free download for ML and I already have the $25 itunes credit that I most likely wouldn't use for anything other than the upgrade to ML and apparently you aren't able to gift apps or an OS in the Mac App store as you can in itunes.