Windows Vista Validation Issues

[tashi]

Microsoft’s WGA server went down August 24th 2007.
Installations were being flagged as counterfeit because they could not be validated.

Forums.

Topic led by Phil Liu MSFT:
ATTENTION - Vista Validation 0xC004C4A5 Errors - PLEASE READ (Or read the latest post for resolution steps)

Until the situation has definitely been resolved, I would advise against shutting down or rebooting your Vista machines.

[tashi]

Windows Genuine Advantage Blog

We've been receiving reports on our forum and through customer service starting last night that Windows Vista validations have been failing on genuine systems. It looks now as though the issue has been resolved and validations are being processed successfully.

Customers who received an incorrect validation response can fix their system by revalidating on our site (http://www.microsoft.com/genuine). We encourage anyone who received a validation failure since Friday evening to do this now. After successfully revalidating any affected system should be rebooted to ensure the genuine-only features are restored.