Microsoft is picking up the pieces this morning as its Windows Genuine Advantage spent the weekend labelling its best customers as pirates and refusing to let them use the software.

A fault in Microsoft's Windows Genuine Advantage (WGA) servers, which authenticate copies of Windows and Office to ensure they are not pirated, identified everyone a pirate.

It disabled many features of Vista, including Aero interface, leaving you with little more than Internet Explorer.Apparently while the problem had to be fixed, site mods had to warn users that swearing was not acceptable.

Microsoft has refused to explain the fault and its blog only tells people how to revalidate affected systems. Already since revalidating some afflicted users have reported that since, they are no longer able to access the Windows Update service.

It is probably just as well the attack did not happen on a weekday as there would have been huge numbers of people affected.