Microsoft redesigned their Certificate of Authenticity (COA) labels in mid- 2006, to support their Software Piracy Protection efforts.

The new COA labels have a transparent 'Port-Hole' which makes it more difficult to remove a COA label from one computer, and affix it to a different computer. The Port-Hole area is an irregularly shaped opening, and reveals fibers of the underlying paper and interwoven metallic threads. The overall appearance of this Port-Hole may suggest that a hole has been worn through the label, as in the picture below, which shows two COA label varieties.

Since the Port-Hole area of the COA is not affixed to the body of the computer, its edges may become further  roughened, or even torn, during normal handling of the computer -- slipping it into and out of a carrying bag, for example. The Port Hole area may also develop some discoloration over time, including darkened areas similar to those shown in the picture below.

Despite its irregular original condition, and the wear and tear described above, the COA label remains a genuine proof of Windows authenticity.

For additional information about the Microsoft Certificate of Authenticity, refer to the following pages on the Microsoft website:

http://www.microsoft.com/resources/howtotell 

http://www.microsoft.com/resources/howtotell/ww/windows/quiz_coa.mspx

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