What we know 4 days after a software update brought down computer systems around the world [Video]

Four days after a faulty software update from a cybersecurity company unexpectedly brought down computers and technical systems across the world, airlines and some other companies are still experiencing delays and other technical problems.The “largest IT outage in history” – prompted by a software update for Microsoft devices late Thursday into the early hours of Friday – caused disorder at airports, outages for 911 services and challenges at healthcare facilities.The outage affected an estimated 8.5 million Windows devices – less than one percent of all Windows machines, according to a Saturday blog post from Microsoft. But the effects were ubiquitous, with airlines, banks, businesses, schools and governments, along with some health and emergency services, across the world affected.Costs from the outage could top $1 billion, Patrick Anderson, CEO of Anderson Economic Group, told CNN. But it’s unclear if – and how – any customers affected will be compensated.Here’s what we …