Event details
We have began rolling out Windows 11 25H2 to our ICT department. Other test phases are planned before rollout to all devices on our estate.
My query is around Hotpatching. We utilise Hotpatching and have done since the beginning of this year. From what I've read, if you upgrade to 25H2 during a non-baseline release month (Feb/Mar/May/Jun/Aug/Sep/Nov/Dec) then it will break hotpatching until the next baseline release.
To retain consistent Hotpatching functionality you need to upgrade during a baseline release month (Jan/Apr/Jul/Oct). Does it matter if you upgrade before or after that months cumulative OS updates on Patch Tuesday (B Release) get applied to devices?
Basically, the ICT devices that have been upgraded this week, pre Patch Tuesday, will Hotpatching continue to function? Ones that are upgraded post Patch Tuesday (planned for the 22nd Oct), will Hotpatching continue to function?
Our global rollout is planned at the end of November (assuming no major issues are reported in testing phases), from what I'm reading that means that they won't receive Hotpatching in December, they'll revert back to the 'normal' process where users will have to reboot to finalise the monthly updates. They'll then start Hotpatching again in February next year once they've received the baseline release in January??
By the time this event happens on the 16th Oct I guess we'll have our answer about the IT devices, just wondered if you had any further guidance? Thanks
- EricMoe
Microsoft
Hi nlmitchell​, this is a great question. For a device to be eligible for a hotpatch it needs to have installed the most current baseline update. So for November and December, devices need to be on the October baseline update in order to be eligible for a hotpatch. So let's look at your example here:
You have a device on Windows 11 24H2 and you update to 25H2 sometime after October 14, 2025 but before November patch Tuesday. And then the 25H2 device takes delivery of the October baseline for Windows 11 25H2. This keeps it on the hotpatch "train" for November and December.
But suppose you upgrade to 25H2 after the November update is released, your device would scan and see that it needs the November non-hotpatch and then it's off the hotpatch train until after the January baseline.
Hotpatching absolutely will keep working, but the requirement for having the baseline update installed prior to the hotpatch release for that quarter does not change.
I hope this helps.
