A message appears at boot-up saying my copy of Windows is counterfeit and asking me to buy a genuine licence. I have a legitimate copy of Windows - it came with the PC and a sticker with a serial number. Gerry Cordon
Several people have suffered from the same problem, and I suspect it may have to do with a quirk in a recent Windows update, but if you have a COA (Certificate of Authenticity) and valid serial number, it should not be a problem.
Microsoft provides details of its COAs at www.microsoft.com/resources/howtotell/en/coa.mspx.
You can check your product key with a program downloaded from http://go.microsoft.com/fwlink/?linkid=52012, and if this does not match your COA, you can change the key with Microsoft's KeyUpdate.exe tool from http://go.microsoft.com/fwlink/?LinkId=50346&clcid=0x409.
This information comes from Microsoft's Phil Liu, who posts in the official Windows forum devoted to WGA (Windows Genuine Advantage) Validation Problems.
If your key is genuine and matches your COA but you still get the message, Liu suggests going to Start|Run, typing WgaTray /b in the box, and clicking OK. Then you "log on and off a couple times". If that doesn't work, ask at http://forums.microsoft.com/Genuine/default.aspx?SiteID=25, where you might get a direct response from Microsoft.
Trivia point: you can check if a copy of Windows XP has already been validated by typing oobe/msoobe /a in the Run box.
