When Microsoft unveiled a new lineup of Windows 10 PCs running on Qualcomm's Snapdragon ARM chips in December, it touted those devices as a way for businesses to transform with "always-connected" computing. However, it turns out those ARM-based devices will also be limited in ways that x86-based PCs are not.

Microsoft offered details about those limitations last Thursday in an online document for developers. After it was spotted by Thurrott and other tech publications, however, the document was retitled and the list of limitations removed.

On the updated page on the Windows developer center, Microsoft now offers a list of solutions for ARM-based devices that don't handle desktop apps in the same way as x86 PCs. In the original version, viewable on the Internet Archive and in screenshots, Microsoft identified six "necessary limitations" inherent to Windows 10 on ARM, including lack of support for x64 apps and improper functioning of assistive technologies and cloud storage apps.

Win 10 on ARM Is Not Win 10 on x86

Among the other limitations for ARM-based Windows 10 PCs that Microsoft identified in its original post: no support for drivers other than ARM64, some non-functioning games, no support for the Windows Hypervisor Platform, and incorrect performance of some apps that assume the device is running a mobile version of Windows.

"This list must have been published by accident, as the software giant removed it over the weekend so only cached copies of the information are available," The Verge reported today. It noted that the ARM-based PCs announced in December are not yet on the market.

In his coverage over the weekend, writer Paul Thurrott said Microsoft's list of limitations ran contrary to "the fantasy that Windows 10 on ARM was the same as Windows 10 on x86."

"Granted, we've known some of the differences from the beginning, and we've vaguely understood that there would be trade-offs for those moving to this new hardware platform," Thurrott wrote. He added that, while Microsoft's list of limitations was "not completely damning, my months-long lackluster experiences with Windows 10 S suggest that the first year will be tough for many who do adopt this platform."

'Always-Connected' PCs from HP, Asus, Lenovo

Announced during Qualcomm's Snapdragon Tech Summit, Microsoft's upcoming always-connected ARM-based PCs include the Asus NovaGo and the HP Envy x2. Lenovo unveiled its first such device in January: the Miix 630, which is expected to arrive on the market this spring.

Writing on Microsoft's Windows blog in December, Terry Myerson, executive vice president of the Windows and Devices Group, said the forthcoming ARM-based Windows 10 devices would run a "new, optimized version of Office 365."

By using Qualcomm's Snapdragon processors instead of Intel's x86 chips, the new Windows 10 PCs promise instant LTE connectivity and long battery life, Myerson said. They also promise security and cost advantages to business users by enabling networking via 4G and, eventually, 5G rather than Wi-Fi.