SIOUX CITY -- Business didn't stop, but it was anything but "as usual" Wednesday after employees on the joint Woodbury County-city of Sioux City computer system shut down their machines while the technical staff investigated viruslike activity.

Officials later said they were among businesses around the world that fell victim to an errant anti-virus program from McAfee Inc., that identified a normal Windows file as a virus. The glitch caused computers to keep rebooting themselves.

John Malloy, information technical director for the Woodbury County Information and Communications Commission, said the incident didn't appear to have damaged any information stored on the network's servers and approximately 800 computers.

However, city and county employees couldn't use their computers while commission staffers isolated the problem and spent hours attempting to get through to McAfee.

"As a precaution we've asked everybody on our network to turn off their work stations until we can assess what's going on," Malloy said Wednesday morning.

If a virus or something else was causing the problems, Malloy said, shutting down all of the computers could stop it from spreading further.

On Wednesday afternoon, Malloy wasn't sure how many computers had been affected by the glitch but said it was "a significant number."

Workers must fix each computer individually, he said.

Slowed services

McAfee confirmed that a software update posted at 9 a.m. Eastern time caused its anti-virus program for corporate customers to misidentify a harmless file. It has posted a replacement update for download.

"We are not aware of significant impact on consumers and believe we have effectively limited such occurrence," the company said in a statement.

Local officials disagree, saying the program sent the network's technology staff into overdrive and limited functions employees in other offices could perform.

Woodbury County Auditor Pat Gill said in some cases, employees had to take in paperwork to enter into the system once they were able to access their computers again.

"It did bring everything to a standstill in other offices," Gill said.

Gary Brown, Woodbury County Disaster and Emergency Services director, said computer service was being restored Wednesday afternoon according to a priority system, with public safety and emergency dispatch stations given the highest priority.

The county's 911 center was operational during the shutdown, but dispatchers lost some functions, such as the ability to track calls electronically, and officers were not able to use computers in their squad cars.

National impact

The city-county computer network was far from alone in its McAfee-induced Wednesday woes.

At Rhode Island Hospital, that 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 Lifespan health system.

Peter Juvinall, systems administrator at Illinois State University in Normal, said that when the first computer started rebooting 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.

-- Journal staff writer Molly Montag and The Associated Press contributed to this report.