Be able to I do wipe and factory reinstate my MBA exclusive of the discs , I have encompassed them somewhere additional than no suggestion where is your goal to fix impressive or to wipe the system previous to selling it. Most of them did the similar by means of my friends MacBook Air previous to giving it to our family member, additional than it is not required to erase the drive. Generate an account for your friend, give him Administrator privileges, then log into his account and eliminate your account. The whole thing you did on the MacBook Air determine to be gone. Most probably, your MacBook Air is running well and your intention to 'wipe' it is not beneficial, i.e., a clean install of the system software to preparation a software tribulations. If that is what you intend, then you determine to necessitate to find your discs.