The COA is a sticker or a label that is often attached to the body of a computer for some versions of Windows or Windows Server. You can typically find the COA sticker on the body of the computer or, for some newer laptops, inside the battery compartment.
COAs and/or product keys should never be purchased separately from the product.
Product Key Concealment
In addition to the features mentioned above, COAs produced from February 2016 may also have an added concealment feature covering part of the Product Key on the COA. The concealment panel consists of a small clear label with removable silver scratch off material that has been applied to conceal a portion of the 25-characters of the product key.
Similar to the removable material commonly found on lottery tickets or prize vouchers, this concealment panel is designed to protect the consumer’s product key from being obtained and used by unauthorized individuals. When a Product Key is required for use by the rightful owner, the silver scratch off material should be removed with a fingernail to reveal the entire 25-characters required to enable activation of the Product.
A simple glance can allow a consumer to observe whether a COA label may have been tampered with. The removable silver material should be fully intact and covering a portion of the 25-characters’ of the product key. If upon receipt, a sufficient amount of the covering silver material has been removed and the entire 25-character product key is exposed, this could indicate that the COA label has been tampered with and there is a potential that the product key has been compromised or used in an unintended manner. If you experience any difficulty using the key for activation, please contact the OEM (Original Equipment Manufacturer) for support.
If the removable silver material is not present on the concealment panel at all, there may be a clear film label retained
in this area, which is evidence that the concealment feature was present and the scratch off material has been
This concealment protection feature has been added to the COA with the Microsoft’s consumer in mind. Microsoft is taking this additional step to protect against unauthorized use of a product key. Consumers should also be aware that product keys are valuable targets for piracy, and it is prudent that precautions be taken to avoid unauthorized access or use of product keys wherever possible.