HELENA — The state’s computer system was restored Tuesday, a day after a major piece of network equipment failed, causing it to shut down.

The state Information Technology Services Division said much of the computer system was working by 10 p.m. Monday. Everything was working normally by 2 a.m. Tuesday.

‘‘Everything is up and functioning,’’ said Dawn Pizzini of the Information Technology Services Division. ‘‘Business as usual has been restored.’’

Technicians are not sure what caused the equipment to fail, but they had ruled out hackers or some type of security breach.

‘‘It was strictly a hardware failure,’’ Pizzini said.

State government workers were stalled Monday as computers across the state wouldn’t work. Wildlife agents were handwriting permits and people were unable to do such things as renew driver’s licenses or get license plates.

Key law enforcement systems were rerouted to avoid any public safety problems.

The IT department would never have predicted Monday’s outage.

‘‘The probability of what happened happening was minuscule,’’ Pizzini said. ‘‘So it was one of those things that would have been extremely difficult to have planned for. We would have never assumed that that many components in that piece of equipment would fail.’’

Pizzini said the IT department is evaluating its long term plan for the network, and changes could be made.

‘‘We’re just glad everything is functioning well and business in the state of Montana is proceeding as it should be,’’ she said.

The state last saw such a computer outage when a virus infected the system about four years ago, officials said.