Skype is pointing the finger at Windows Update for a critical system crash that wiped out the VoIP service for two days. Previously they had reported that the outage was to do with its own software.
In a statement posted on the company's support page, the company claims: "The disruption was initiated by a massive restart of our user's computers across the globe within a very short timeframe as they re-booted after receiving a routine software update." This is presumably the Windows updates that were sent out on Patch Tuesday last week, which required the PC to be restarted.
"The abnormally high number of restarts affected Skype's network resources," the company adds. "This caused a flood of log-in requests, which, combined with the lack of peer-to-peer network resources, prompted a chain reaction that had a critical impact."
Skype, which hasn't suffered serious problems with Windows Update before, says its normal failsafes proved ineffective. "Normally Skype's peer-to-peer network has an inbuilt ability to self-heal, however, this event revealed a previously unseen software bug within the network resource allocation algorithm which prevented the self-healing function from working quickly. Regrettably, as a result of this disruption, Skype was unavailable to the majority of its users for approximately two days."