Antivirus vendor McAfee Inc. confirmed that a software update caused its antivirus program for corporate customers to misidentify a harmless file. It has posted a replacement update for download.
Online posts indicated that thousands of computers running Windows XP with Service Pack 3 were affected.
At Rhode Island Hospital, the state's biggest, the computer lock-up prompted personnel to divert emergency room visitors without traumas to other hospitals. The hospital also postponed some elective surgeries. Patient care continued uninterrupted using backup procedures, according to Nancy Jean, spokeswoman for the health system.
Peter Juvinall, systems administrator at Illinois State University in Normal, said the first computer started rebooting before 9 a.m. It quickly became evident that it was a major problem, affecting dozens of computers at the College of Business alone.
"I originally thought it was a virus," he said. When the tech support people concluded McAfee's update was to blame, they stopped further downloads of the faulty software update and started shuttling from computer to computer to get them working again.
Intel Corp. also appeared to be one of the victims, according to employee posts on Twitter. Intel did not immediately return calls for comment.
