Please follow this WGA troubleshooting procedure:
1. Download and install the WGA Diagnostic Tool: http://go.microsoft.com/fwlink/?linkid=52012
2. After running the WGA Diagnostic Tool, click on the "Validation" tab and then click on "Copy to Clipboard".
3. Next, paste the results in a reply to this thread.
4. A WGA troubleshooting specialist will analyze the data and recommend an appropriate solution.