Microsoft officially unveiled Windows 10X last year, alongside its Surface Neo dual-screen device. Windows 10X is an ambitious effort to redesign the operating system for devices that have dual screens and even foldable displays. We’ve started to see some of this hardware at the Consumer Electronics Show (CES) this week, but it’s all lacking the key software element: Windows 10X.

While Microsoft has promised Windows 10X devices from Dell, HP, Lenovo, and Asus, most of the PC makers aren’t ready to show what they’re planning just yet. Lenovo unveiled its ThinkPad X1 Fold this week — a $2,499 PC with a folding OLED screen — but it will crucially ship this year with Windows 10 Pro instead of Windows 10X. Lenovo is promising a Windows 10X version later, but it’s unclear when exactly that will happen.

Lenovo’s X1 Fold looks like a primary candidate for Windows 10X, but the Chinese PC maker is pressing on with a launch without it. That either suggests Microsoft is behind on Windows 10X or Lenovo is pushing ahead aggressively and likely prematurely.

Windows 10X is key to a device like the X1 Fold because Microsoft is building in a variety of ways to handle apps across multiple displays directly into the operating system. Lenovo has instead built its own software to sit on top of Windows 10 to make it more friendly for separating apps, but that’s exactly what Windows 10X is supposed to offer natively.

Microsoft has been working on 10X for years, mindful that Intel and other OEMs were pushing toward foldable and dual-screen hardware quicker than Windows could keep up. Microsoft wants Windows 10X to be ready for PC makers to take advantage of this new wave of hardware, but it’s clearly still months away from being ready.

Asus, Dell, and HP have also not yet revealed any dual-screen or foldable Windows devices, but most of them are playing around with some prototype ideas. Dell introduced concept foldable and dual-screen laptops this week, and Asus introduced a smaller 14-inch dual-screen laptop. All of these devices, including Intel’s folding concept, are also running a standard version of Windows 10 that’s not designed with this new hardware in mind.

It’s fair to say that Windows 10 looks janky and awkward in dual-screen and foldable hardware demonstrations. It reminds me of the early days of touchscreen laptops, back when Windows 7 wasn’t designed and built around screens you could touch. Microsoft then went all-in on touchscreens with Windows 8 to much criticism, and is now taking a careful approach with Windows 10X.

PC makers look set to announce more of these foldable and dual-screen devices this year, but any haste will be met with the realization that these machines desperately need something beyond Windows 10. During my brief time with the Surface Neo, it was clear that Microsoft has solved a variety of potential pain points with this hardware by running Windows 10X. PC makers and Microsoft also have to weigh up what multiple displays do to battery life, how apps run, and the pure weight and thickness of a device.

We’ve already seen Samsung rush to market early with a foldable Android device that needed to be re-engineered before it even hit store shelves. If PC makers like Lenovo rush into foldable and dual-screen hardware without Windows 10X, they need to have some stunning software alternatives to avoid souring the market.

A lot rests on Windows 10X being a success for these devices. There’s no guarantee it will even be good enough for this hardware, or get the app support it requires. Microsoft needs to deliver the software and experiences that make dual-screen and foldable hardware shine. We’re still waiting to hear more about 10X, but 2020 has only just begun and Microsoft’s Build developer conference kicks off in May followed by Computex in June. For now, all of the potential hardware for 10X looks lost without it.