Late last night we started receiving reports from readers experiencing problems with Windows Genuine Advantage authentication. Users of both Windows XP and Windows Vista were writing to say that they could not validate their installations using WGA, and one user even said that his installation was invalidated by the service.

We contacted our sources at Microsoft, who told us off the record that the company is aware of a major WGA server outage affecting users across the globe. The Windows Genuine Advantage support forum has exploded with complaints, as a result, and Phil Liu, WGA project manager, says that he won't sleep until the problem is fixed. Windows Vista and XP are affected, 32- and 64-bit versions.

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