Microsoft now warns customers of specific bugs and compatibility problems that prevent it – at least temporarily – from offering Windows 10 PCs the latest feature upgrade.

After Microsoft re-released the October 2018 Update – labeled 1809 in the company’s yymm format – on Nov. 13, it expanded the section titled “Current status of Windows, version 1809, Windows Server 2019, and Windows Server, version 1809” on the definitive Windows 10 update history support page, adding more information about blockers.

Five blockers currently stymy installation of 1809 to, among others, PCs running a pair of Trend Micro security packages and machines relying on new Intel display drivers. Rather than offer 1809 to such systems, Microsoft simply refuses to give them the upgrade.

Microsoft explains upgrade blocking

Microsoft spelled out upgrade blocking to those who had no inkling of the practice.

“Blocking the availability of a Windows 10 feature update to devices we know will experience issues is a key aspect of our controlled rollout approach to provide users with a great update experience,” Microsoft said. “We decide what to block based on user impact from closely monitoring feedback and device diagnostics. If we detect that your device may have an issue, such as an application incompatibility, we will not install the update until that issue is resolved, even if you ‘Check for updates’ [in Windows 10]. We do this so that you avoid encountering any known problems.”

Something not mentioned was that Microsoft practiced upgrade blocking for decades. For example, it required pre-Windows 10 versions to have been dealt very specific updates prior to the OS accepting and installing a service pack or upgrading to an entirely new edition. “Some updates require a prerequisite update before they can be applied to a system,” Microsoft explained in a support document. Microsoft had also frequently declared that a just-issued security update wouldn’t install sans one or more previous updates being detected in place._