Windows 11 25H2 "Point in time restore" seems to reset System Protection to 2%

Question

TL;DR:&nbsp;On Windows 11 25H2, the new&nbsp;"Point in time restore"&nbsp;feature (Settings &gt; System &gt; Recovery) shares a&nbsp;single VSS shadow-storage allocation&nbsp;with classic System Restore. It periodically re-applies its own default of&nbsp;~2% of the volume, which overrides the System Protection "Max Usage" I set and&nbsp;purges existing restore points&nbsp;- and it does this&nbsp;even when the feature is turned off. I'd like to confirm whether others see this and whether it is by design.EnvironmentWindows 11 Pro, 25H2 (build 26200.8875)Single internal SSD, C: ~488 GB, NTFS"Point in time restore" was enabled by a recent update without my action; I had since turned it off.SymptomI set System Protection (System Protection &gt; Configure &gt; "Max Usage") for C: to 6%. Within a day or two it silently reverts to&nbsp;exactly 2% of the volume&nbsp;(9.76 GB on my 488 GB drive). When it drops, VSS deletes older restore points to fit the smaller cap - visible in Event Viewer,&nbsp;System log, source volsnap, Event ID 33&nbsp;("The oldest shadow copy of volume C: was deleted to keep disk space usage ... below the user defined limit"). So I lose restore history I was relying on.It resets to&nbsp;exactly&nbsp;2% every time - a computed default, not a random value.What I found: the two features share ONE allocation (reproducible)There is a single VSS shadow-copy storage association for C: with one Maximum. Classic System Restore and "Point in time restore" are two front-ends to that same number:Elevated prompt: vssadmin list shadowstorage - note "Maximum Shadow Copy Storage space" for C:.Settings &gt; System &gt; Recovery &gt; Point in time restore - set its size (I used 15 GB).Re-run vssadmin list shadowstorage - the Maximum is now 15 GB,&nbsp;and&nbsp;the classic System Protection "Max Usage" now also shows 15 GB.So setting Point-in-time's allocation writes the same maximum System Restore uses. The reset to 2% is therefore Point-in-time re-applying&nbsp;its own default&nbsp;to that shared allocation - which is why my System Protection setting keeps getting overridden and restore points get purged.Two details that stand outIt resets even with the feature OFF.&nbsp;Point-in-time had been disabled for about two weeks (its stored allocation left at the 2% default) and the reset still happened. So a background component re-applies the 2% regardless of the on/off toggle.The coupling is one-way.&nbsp;Setting the value via Point-in-time updates both; setting it via classic System Protection updates the live maximum but does&nbsp;not&nbsp;update Point-in-time's stored value. Point-in-time keeps its own independent allocation, and that stored value is what gets re-applied.What it is NOTNot a Windows Update / servicing event - no quality or feature update installed on the days it reset (only Microsoft Defender definition updates, which do not touch System Protection).No reboot, crash, or third-party backup software involved.Mechanism, as I understand it"Point in time restore" appears to be a&nbsp;whole-volume revert&nbsp;- it reboots into WinRE (the Recovery partition) and rolls the entire C: volume back to a snapshot - whereas classic System Restore is a&nbsp;selective&nbsp;restore of the registry and system files that runs from the live OS. Both use the same VSS shadow copies of C:, which is why they share one storage allocation. (I am confident about the shared-allocation and reset behaviour, which is reproducible above; the internal revert mechanism is my inference.)QuestionsIs Point-in-time overriding the user's System Protection allocation, and purging restore points to fit,&nbsp;by design?How can the System Protection "Max Usage" be made to&nbsp;persist&nbsp;- i.e. stop Point-in-time re-applying its 2% default?Can Point-in-time's allocation be raised, or its re-assertion disabled,&nbsp;without&nbsp;disabling classic System Restore?Is there a supported registry or policy setting for this? I could find no honored DiskPercent / percentage value on 25H2.If you want to check your own machineRun vssadmin list shadowstorage (elevated) before and after setting Point-in-time's size, and watch whether your System Protection "Max Usage" holds over a few days or reverts to ~2%. I'd appreciate confirmation - or contradiction - as I'm trying to establish whether this is universal 25H2 behaviour or specific to my setup. Thanks!

stormin · Answer

Supplement (follow-up): confirmed - the Restore Point max is forced to match Point-in-time's stored valueA follow-up test settles whether the reset is a hardcoded 2% or simply Point-in-time's stored allocation being re-applied. It is the stored value:I set Point-in-time's allocation to 15 GB, then set the classic System Protection "Max Usage" to 29.3 GB (6%) through the normal UI. vssadmin list shadowstorage confirmed the shared Maximum was 29.3 GB.A day later, with no action from me, the Maximum had been forced back down to 15 GB - Point-in-time's stored value - not the 2% default (which would have been 9.76 GB).So the earlier resets only landed on 2% because that was Point-in-time's default stored allocation. Whatever value Point-in-time holds is forced onto the shared Restore Point maximum, overriding whatever I set in classic System Protection. In practice the System Protection "Max Usage" cannot hold any value different from Point-in-time's stored allocation - Point-in-time's number wins on the next reset, and restore points are purged to fit.Practical upshot for anyone hitting this: set the size you actually want in the Point-in-time UI (Settings &gt; System &gt; Recovery), not the classic System Protection slider - that's the value that gets re-applied, so it's the one that sticks.&nbsp;

damont · Answer

This is exactly exactly what I'm experiencing Have been using the system restore since I've been using Windows I could not figure out what was going on I didn't even know about this point of shared time thing.

the settings are so weird now and difficult to find (muscle memory -wise) I would have normally went through all of them but, alas....

I just went in and changed it to 5% keep an eye on it with this terminal that you listed. I didn't totally understand your whole thing but it was very well broken down. from what I could see it was exactly what was happening to mine. Keeps resetting back to 2% exactly and when I went to go restore my system the other day there was no restore points.ZERO! Except for two backups from 2025 .

Sys Restore is always one of the 1st things i check when installing or reinstalling windows. sometimes it has been set up in the off postion idk why... Also I noticed that recently , and after Windows 11 was Already installed a while, that in my C drive now says the thing about back up drive shouldn't use restore points because it may more and more shadow copies being lost etc.. Which it never said that prior i'm no developer as you can tell. but I do know my way around. Something somebody else said duplication In the comments made me think of the service that I didn't know what it was ReFS Dedup service, I have no idea if that has anything to do with anything but I just went to revert systems Services and reverted to start to demand, manual.

i appreciate your very well broken down summary of this issue He's still not alone Now I know how to keep an eye on it and that there's another setting I tried turning it off I think maybe the difference their old version does like 1% 2% 3% Looks like the newer settings version does like 4.9% 5.4% et cetera I couldn't get it to go to 5% exactly but it came up as 5% on the old version Weird

theaoper · Answer

You're right on the money. Both&nbsp;System Restore&nbsp;and the new&nbsp;"Point in time restore"&nbsp;feature use the&nbsp;same VSS (Volume Shadow Copy) storage area on your drive. They're not separate pools – they share the same shadow-storage allocation.

kirashi · Answer

I'm experiencing the same behaviour on all my systems, which has BROKEN how Synology Active Backup for Business (ABFB) functions. ABFB still works, however, it's now incapable of doing incremental backups to our Synology NAS, likely because it relies on the Disk Space Usage setting in the Configure menu on the System Protection tab of the System Properties window. (Run the "sysdm.cpl" from the Run... box.)

ABFB backups now copy the ENTIRE disk (usually around 400GB) over the network for every backup job, instead of an incremental backup (much smaller 60-120GB depending on how much data has changed). I also worry the Synology NAS is no longer de-deduplicating the data (and therefore taking up way more space), but it hasn't been long enough to identify a storage trend yet.

Like stormin, I share the same questions. Until answered, our backup strategy has been affected by a decision Microsoft did not communicate in a way that I saw it. This is absolutely unacceptable as it breaks a workflow critical to everyone using Synology ABFB to backup their computers.

What will Microsoft be doing to resolve this impact for Synology ABFB users?