What is the difference between OEM CD w/COA and OEM CD w/KEY?
The only difference between these 2 products is the way that the key number comes. The OEM w/ COA comes with the key number (product key) on an actual Certificate of Authenticity (COA) from Microsoft. The OEM w/ KEY just has the serial number on a label on the back of the cd sleeve. Some people feel more secure getting the product key on a COA while others are willing to save money and just get the key number on a label. Both are fully licensable and able to be registered with Microsoft.
