The California Department of Motor Vehicles says a major computer problem is affecting offices around the state.
The DMV said Tuesday that crews worked all night to rebuild the system after the outage began Monday due to a hardware failure.
Officials said the computers were not hacked or targeted.
Driver license and vehicle registration services are affected. But offices without computer services were still providing driving tests, making appointments for customers to return, helping with paperwork, and answering customers' questions.
The DMV advised drivers to check www.dmv.ca.gov or call 1-800-777-0133 to see if their local field office was affected. The department's online services were not harmed.
Officials did not have an estimated time when services would be restored.