
Microsoft's 'worst-selling product of all time' sold just 11 copies, eight of which were returned to the tech giant.
Even tech giants like Apple have occasionally released products that absolutely flopped and have become cautionary tales. These days, Microsoft can sell almost anything, even the relatively unpopular Xbox Series consoles have shifted tens of millions of units worldwide.
But there was a point in time when the future of Windows wasn't so certain.
In the mid-1980s, Microsoft was collaborating with IBM on an alternative to both Windows and the DOS system it depended on, OS/2.
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While OS/2 ultimately failed to overtake Windows commercially, it was highly regarded among PC users. Despite its decent reputation, one particular version of OS/2 became Microsoft's worst-selling product in history. The software sold a total of 11 copies in its lifetime, eight of which were returned.
At the time, computers were becoming mainstream but hadn't quite reached universal adoption. Many companies were digitising operations whilst still operating under 1960s-style budgeting mentalities.
Computers were also extremely expensive, but at the same time, they represented the future. So, convincing corporate finance departments to approve massive PC expenditures was often possible.

That said, PC technology was evolving at breakneck speed in the late 1980s. Within just a few years, they progressed from 4.77 MHz 8088 CPUs with 8-bit buses to 386DX processors running up to 33 MHz with 32-bit buses. Graphics evolved from monochrome to SVGA, boasting 256 vibrant colours.
The Mach 20 itself wasn't particularly popular, yet it was apparently successful enough for Microsoft to justify releasing a dedicated version of OS/2 specifically for this hardware.
That specific release purportedly became Microsoft's worst-selling product ever.
"One of my former colleagues spoke with the person who took over from him as the support specialist for OS/2 for Mach 20," explained Raymond Chen, a developer who has been involved in the evolution of Windows for more than 30 years. "According to that person's memory [...] a total of eleven copies of 'OS/2 for Mach 20' were ever sold, and eight of them were returned."
He added: "That leaves three customers who purchased a copy and didn’t return it. And the support specialist had personally spoken with two of them."
Whilst it's amusing to imagine an operating system achieving just 11 sales, the failure isn't actually surprising. This specific release required the obscure Mach 20 hardware, and OS/2 itself remained poorly understood outside hardcore tech enthusiasts. Most purchasers who returned it likely bought without fully understanding what they were getting into.
But what happened to the three customers who actually kept the software, I guess we'll never know...