The way to do this is either from the command line:

Vista:

• Less Information:<strong> slmgr.vbs &ndash;dli</strong>
• More Information (verbose):<strong> slmgr.vbs &ndash;dlv</strong>

Windows 7:

• Less Information:<strong> slmgr.vbs /dli</strong>
• More Information (verbose):<strong> slmgr.vbs /dlv</strong>

Or using the GUI.

1. Go to the Control Panel, select System and Maintenance, then System.
2. In the Windows Activation section make sure it says, &ldquo;Windows is activated.&rdquo;

Note: If you see &ldquo;X days to activate. Activate Windows now,&rdquo; select the link to open the activation wizard, then follow the steps to activate your license.

– Main.FredPettis - 2010-08-14