Please follow this simple troubleshooting procedure:
1. Download and run the MGA Diagnostic Tool: http://go.microsoft.com/fwlink/?linkid=52012
2. After running the MGA Diagnostic Tool, click on the "Windows" tab and then click on "Copy".
3. Next, visit the following website and create a post in the "WGA Validation Problems" forum and paste the results of the WGA Diagnostic Data in a detailed post.
http://forums.community.microsoft.com/en-US/genuineoffice/thread/20c7a9be-37f8-40d3-a2ac-fcf6f2f95f57
4. A WGA troubleshooting specialist will analyze the data and recommend an appropriate solution.
Please note: I am not a Microsoft employee...only a voluntary forum contributor.