The US nuclear weapons force still uses a 1970s-era computer system and 8-inch floppy disks, a government report has revealed.
The Government Accountability Office said the Pentagon was one of several departments where "legacy systems" urgently needed to be replaced.
The report said taxpayers spent $61bn (£41bn) a year on maintaining ageing technologies.
It said that was three times more than the investment on modern IT systems.
The report said that the Department of Defence systems that co-ordinated intercontinental ballistic missiles, nuclear bombers and tanker support aircraft "runs on an IBM Series-1 Computer - a 1970s computing system - and uses eight-inch floppy disks".
"This system remains in use because, in short, it still works," Pentagon spokeswoman Lt Col Valerie Henderson told the AFP news agency.