I bought a copy of this from softdealworld which is the first item on Google. It was cheap and I had no problems with receiving the product but only realised when I sent an email that it was from China and a friend has said how can I be sure it is an authentic Microsoft produce. I have now seen on the web that there are issues with non validated software and wondered whether I can check through the licence code 99994-605-890-074 X12-08297 is a proper version before I install it.