^^ Is your Windows genuine or a pirated one? Because the above mentioned methods will only work if your Windows is actually genuine but somehow your computer is detecting it as pirated.
Microsoft sought to curtail this activity with the release of Windows Genuine Advantage, which stealthily installed itself onto millions of PCs by way of a high-priority “update.” (Sound familiar?) Windows Genuine Advantage consisted of two parts, one to actually validate the OS and another to inform users whether they had an illegal installation: In 2006, Microsoft said it had found about .
The desktop background can be reset to anything else in the usual ways, but every 60 minutes it will change back to the plain black background. This will continue to happen until that copy of Windows is genuine.