This copy of windows is not genuine

HiI installed Windows 7 on my computer about 10 months ago - after purchasing the OEM disks from an online shop together with other computer hardware for a system I was building. I activated Windows, and have used the system without issue ever since. However, in the last couple of days I've noticed a small message in the bottom right corner of my desktop stating that "this copy of windows is not genuine". What does that mean? Has the shop sold me a fake copy? Why have I been able to install and use this OS for 10 months? Does this have any consequences for the use of the system?Regards,Peter

Activation has not succeeded and the key number you received may not be genuine. Contact Microsoft Anti-Piracy for assistance: Protect Yourself from Piracy

The lack of a genuine product key can either mean that it was never entered as part of the sale, it was a pirated key, or hardware changes de-activated the license. See also:

Genuine Windows: frequently asked questions - Microsoft Windows