Unfortunately, there are a number of High Quality Counterfeit versions selling on the Internet today, and some would even fool professionals! While these appear to be legitimate products, they are not - often originating in China and bought cheaply then resold in the UK as genuine - they not only deprive genuine resellers, but for you, the customer, they can be a nightmare and a waste of your hard earned money, and contain viruses and other malware which can compromise your computer system. In addition, the software *will* eventually be Blocked by Microsoft, and cease working.
They will install, and often, do not require activation, as genuine products do. After activation, and as part of normal updates, (even on non activated counterfeits)your PC will download the Office Genuine Advantage Tool from Microsoft - this will result in messages on your screen, telling you that you do not have Genuine Microsoft Office
After installation, the product, if FILE - HELP is selected on Outlook, it will say OUTLOOK 2010 PART OF MICROSOFT OFFICE PROFESSIONAL PLUS 2010 or PART OF MICROSOFT OFFICE ENTERPRISE 2010, instead of the correct "Part of Office Professional 2010".
So, how can the average person tell? Below is the only method currently of identifying, before purchase, a Genuine Product - the "Certificate of Authenticity", which is on the top of every retail box.
There are pictures, to assist you in determining if your Product is a high quality counterfeit item: