Windows 10 will be rolled out to about 29,000 PCs at the city council, a major shift for an authority that has been running Linux for more than a decade.
The rollout will begin in 2020 and is expected to be completed by the end of 2022 or early 2023, at a cost of around €50m.
Munich was once seen as a champion of open-source software, a reputation earned following its decision in 2003 to switch to a Linux-based desktop, which came to be known as LiMux, and other open-source software.
Munich mayor Dieter Reiter said the move to Windows 10 is necessary to simplify the management of the city's desktops. By switching the Windows 10, he says the council will no longer have to run two desktop operating systems side-by-side. Reiter was referring to a longstanding practice at Munich of running both LiMux and a minority of Windows machines, which are kept for applications not compatible with Linux and where virtualization is not an option.
"We always had mixed systems and what we have here is the possibility of going over to a single system. Having two operating systems is completely uneconomic," he said, speaking at the full council meeting yesterday where the move to Windows was approved.
There is disagreement over what proportion of machines run Windows, with critics of the current setup saying it is as high as 40% PCs, while others argue it stands at about 20%. That said, the council has been running both systems side-by-side for more than 10 years, but has only recently highlighted managing twin systems as a problem.
Beyond simplifying the city's desktop estate, Mayor Reiter said a return to Windows was needed to resolve unhappiness with the performance of Munich's IT.
"I've never said I'm an expert in IT procurement. But I'm backed by 6,000 co-workers who also aren't satisfied with the performance of the existing systems," he said.
Last year, a study of Munich's IT by consultants Accenture and arf found the authority took too long to update software and fix bugs, resulting in "obsolete, partially unsafe, usually extremely cumbersome IT, leading to lots of wasted time and productivity". However the blame for these problems was not laid at the feet of open-source software, but mostly on a lack of coordination between the more than 20 IT departments serving the city.
Dr Florian Roth, leader of the Green Party at Munich, questioned why the council would spend so much money swapping operating systems when the use of open-source software was not to blame for the city's IT failings.
"We're agreed that improvements to our IT are absolutely necessary. But whether the expensive model of a complete rollback to Microsoft, with the associated financial costs, is the answer is open to question," he said.
Alongside the move to Windows, the council agreed to carry out a 6,000-seat pilot of Microsoft Office 2016, which will be run on virtual machines.
The outcome of this trial will be debated by the council at the end of 2018, and be used to inform a decision on whether to replace the open-source office suite LibreOffice with Microsoft Office. If the move to Microsoft Office is approved, it is expected to begin in 2021 and be completed by the end of 2023.
The Windows 10 migration and Office 2016 trial will coincides with a restructuring the city's IT departments and a push to extend the use of virtualization across the authority.