I bought a disc that was supposed to install Mavericks 10.9 onto my iMac. After much time when it appeared to be working it then asked me to install a disc that was formatted to install this software. I assumed that a disc supposed to install a type of software would be formatted for that purpose! I sent many emails explaining the situation, in detail. They then asked me to send photos of the problem which was completely ridiculous as I had fully explained what had happened. By this point I just wanted a refund as I was tired of dealing with this unprofessional company. If I could give them minus 10 stars I would. Eventually I did manage to install mavericks for free via Apple advice. I would not recommend this company at all. And, bye the way, I would still like a refund.