Windows’ hotpatch feature has long promised one thing: security updates without the dreaded restart. But for the next two months, that promise is being quietly set aside for affected machines.
According to Neowin, citing Microsoft, hotpatch PCs will be forced to restart to apply the September and October 2026 Windows updates, temporarily disrupting the restart-free experience the feature was designed to deliver.
What’s happening with hotpatch updates
Hotpatching lets Windows apply certain security patches to already-loaded code in memory, meaning the changes take effect without you having to reboot. When it works as intended, you can install a security update and keep working — no “getting ready to configure updates, don’t turn off your PC” screen required.
That is exactly the experience on the line for the upcoming updates. Microsoft has confirmed that the September and October 2026 security releases won’t be fully hotpatchable, so affected machines will need a restart to complete installation.
Why Microsoft can’t hotpatch these updates
Hotpatching isn’t a catch-all solution — it comes with real technical constraints. A patch can only be applied without a restart if it fits within a specific size limit and only modifies code that doesn’t require restructuring the surrounding module.
When a security update introduces changes that fall outside those bounds — for example, new routines that don’t fit the hotpatch template — Windows has no choice but to apply the update the traditional way, which requires a reboot. Based on the details reported, the September and October 2026 updates appear to contain changes of this nature.
The silver lining is that this is a temporary situation. Microsoft is treating it as a short-term limitation rather than a permanent loss of the capability, and expects hotpatching to resume its normal restart-free operation afterward.
The background on restart-free updates
Microsoft has been pushing toward seamless security updates for years, and hotpatching is a central part of that strategy. The whole point is to reduce the friction that plagues routine patching — the interrupted work sessions, the coordinated restarts across enterprise fleets, the “configure updates, 100% don’t turn off” screens that show up at the worst possible moment.
For IT administrators managing a large fleet, restart-free updates are especially valuable: they remove a whole class of scheduling headaches and let security patches land without disrupting continuous operations. That’s why the temporary suspension matters more for organizations than for most home users.
Microsoft appears to be treating this as an unavoidable short-term trade-off rather than a design flaw. The September and October 2026 updates simply contain security changes that don’t fit within hotpatching’s constraints, so the restart is the fallback path.
What this means for you
If your PC supports hotpatching, plan to leave it powered on and available during the window when the September and October 2026 updates install. That means scheduling the update around a time when you can safely restart — overnight or during a lunch break, for instance.
For most users, the impact is minor. You’ll simply see a restart prompt where you might not have expected one. But if you’re running unsaved work or relying on a machine to stay up continuously, factor the restart into your schedule rather than assuming the update will apply silently in the background.
How to get it and what to do
The updates will arrive through the normal Windows Update channel, so there’s no special action required to receive them. To minimize disruption, you can set an “active hours” window in Windows Update to defer restarts during the times you’re most likely to be using the PC.
Microsoft is expected to clarify the exact rollout timing and which builds are affected as the updates approach. For now, the simplest approach is to keep Windows Update enabled and be ready to restart when prompted.
Source: Neowin
Over to you: Will you schedule your September Windows update around a planned restart, or hope your machine stays in hotpatch mode?
