A failed attempt by the city Tuesday to marry a new computer mainframe with 40-year-old software will cause a third consecutive day of delays for people on all islands who need driver’s licenses and vehicle registrations.

City officials, who maintain the statewide database accessed by all counties, began noticing problems with the system Monday morning and tried to reboot it twice Tuesday afternoon with no luck, leaving them scrambling to figure out what to do next.

Following the failed reboot attempts, the June 30 deadline for motor vehicle registrations was extended to July 7.

The city also announced late Tuesday that it will limit service at its driver’s license centers today, where only scheduled road tests and walk-in road tests will be offered, if available. The city’s nine satellite city halls will continue to provide services other than driver’s license transactions.

And city workers are planning to work overtime from 8 a.m. to 4 p.m. Saturday to staff the Kapalama Driver Licensing Center. The Kapalama Satellite City Hall will not open Saturday.

“We’ve had a problem for the last two days, and I know it affected so many of our residents, but we do want to apologize to everybody for that,” Sheri Kajiwara, the city’s Customer Services director, told reporters Tuesday outside Honolulu Hale.

Before the failed reboot, Kajiwara had said that today “should be a normal day.”

And Keith Ho, the city’s deputy director of information technology, was already promising “to make sure it doesn’t happen again.”

But after Kajiwara and Ho spoke to reporters, they learned that two attempts to reboot the system had failed.

Sirius sold the IBM mainframe to the city at a cost of “a little under $1 million a year,” Ho wrote in an email to the Honolulu Star-Advertiser. The five-year contract began last month, Ho said.

The city tried to make “upgrades” last month, Ho told reporters. And on June 21 “some new code” was added and “the system was OK,” Ho said.

But when the system was shut down Sunday for routine backups, Ho said, “that’s when we experienced some problems. That’s when all the problems happened. So Monday morning, that’s when we started to see performance problems. … It’s processing. It’s just slow. This is old software.”

The system was running slowly at 8 a.m. Monday. By 9:30 a.m. city officials realized they had serious problems.

“We’re not experienced with the new equipment,” Ho said. “We were advised to reboot it. It didn’t change anything.”

Likely thousands of people needing state identification, driver’s licenses and vehicle registrations have been affected, said Chase Masuda, the city’s acting licensing administrator.

“We’re going to be looking at a lot of people,” Masuda said. “This is our busiest time, summer.”

The problems also come at the end of the month, when vehicle registrations expire.

If the computer system is not fixed by Saturday, when July starts, Maui County officials are considering asking police to waive citations to drivers with vehicle registration tags that expire this month, said county spokesman Rod Antone.

“It’s not going to be their fault if they still have June tags in July,” Antone said. “It’s not their fault they can’t register their vehicles.”

Like the rest of the state, Maui County workers faced delays assisting people whose information is stored on the statewide mainframe in Honolulu, Antone said.

“Yes, we are experiencing slower response times,” Antone said. “It’s affecting vehicle registration, state IDs, moped registration, out-of-state license transfers, anything that affects Maui County having to access the city and county’s mainframe. However, we can do taxicab renewals and disabled-parking placards.”

Naomi O’Dell, vehicle registrar and licensing administrator for Hawaii County, said her staff had already faced two days of frustrations from county residents and were looking at a third.

“It is impacting us heavily,” O’Dell said.

Asked for an estimate of how many people on Hawaii island had been turned away in frustration, O’Dell said, “I have no idea. It’s a huge number.”

The problem also will likely delay mainland financing for new vehicles bought in Hawaii, said Dave Rolf, executive director of the Hawaii Automobile Dealers Association.

Buyers won’t be affected, Rolf said, but Hawaii auto dealers will have to explain to mainland lenders why their names are not listed as the lien holder on the vehicle’s title, Rolf said.

“I understand the issue isn’t as much of an issue with local banks because they have relationships with the dealers,” Rolf said in an email to the Star-Advertiser.