FRANKFURT, Germany - A two-day outage that left millions of Skype users unable to use the popular Internet phone service was caused by an abnormally high number of restarts after people had downloaded a Windows security update, the company said Monday.
The worldwide outage, which began on Thursday and ended on Saturday, left millions of Skype users unable to log on to make phone calls or send instant messages.
Luxembourg-based Skype Ltd., part of online auction giant eBay Inc. (nasdaq: EBAY - news - people ), has more than 220 million users in total but typically has 5 million to 6 million users online at any given time. In January, Skype reported that it had counted 9 million users online at one time.
In an update to users on Skype¡¯s Heartbeat blog, employee Villu Arak said the disruption was not because of hackers or any other malicious activity.
Instead, he said that the disruption ¡°was triggered by a massive restart of our users¡¯ computers across the globe within a very short timeframe as they re-booted after receiving a routine set of patches through Windows Update,¡± Arak wrote.
Microsoft Corp. (nasdaq: MSFT - news - people )
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