Need to resize System Reserved partition

KevTech said:

from what I was told is a mandatory partition on GPT disks.

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It's NOT mandatory.
MS put it there for possible future use.

Since 2021, MS hasn't used it on Win 11.
Since 2020 MS hasn't used it on Win 10.

To me... that means it doesn't need to be there.



From your Wikipedia link...

The Windows operating system uses this partition for compatibility purposes. No meaningful data is stored within the MSR. Rather, when compatibility needs arise, Windows shrinks this partition to make way for other special-purpose partitions, which may contain data.

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It's just a space holder.
People with partitioning software... don't NEED it.

On a side note: People with decent 3rd party backup software, don't need the Recovery partition either.
But that's another whole ball of wax.

Ghot said:

It's NOT mandatory.

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From my source at Microsoft who I just emailed about it.

Deleting the MSR can lead to system instability and may cause issues with Windows updates or other system functions.

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KevTech said:

From my source at Microsoft who I just emailed about it.

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NOT TRUE.
I've only had one update fail and that was because I removed those two reclaimable packages from the Component Store.

I've had ZERO... BSODs on Win 10 or Win 11.

So your MS buddy must be worried your computer will... fall over (instability), or something.


In the future, please address the person who made the topic, which wasn't me. ^^

Ghot said:

So your MS buddy must be worried your computer will

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Engineer who worked on Win 10/11.

KevTech said:

Engineer who worked on Win 10/11.

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Didn't read that last sentence, did you? :/

I'd be tempted to reinstall the whole bloody thing, set a bigger EFI partition and then restore the backup on top.

I'm with @KevTech here to be honest. The fact that the partition hasn't been used yet doesn't mean it's useless. MS knows it's there and nobody knows what it could be used for at some point. Maybe it won't be used - maybe it will.

Obviously MS cannot say "yes, delete it, it's pointless". Probably nobody within MS knows that anyways.

He pointed me to another source.

tony359 said:

I'd be tempted to reinstall the whole bloody thing, set a bigger EFI partition and then restore the backup on top.

I'm with @KevTech here to be honest. The fact that the partition hasn't been used yet doesn't mean it's useless. MS knows it's there and nobody knows what it could be used for at some point. Maybe it won't be used - maybe it will.

Obviously MS cannot say "yes, delete it, it's pointless". Probably nobody within MS knows that anyways.

Click to expand...

It's your comp my friend... do it the MS way...

1. Search for cmd. Press-and-hold or right-click on Command Prompt in the results, and select Run as administrator.
2. At the command prompt, type mountvol y: /s and then hit Enter. This will add the Y: drive letter to access the System Partition.
3. Switch to the Y drive by typing Y: and press Enter. Then, navigate to the Fonts folder by typing cd EFI\Microsoft\Boot\Fonts. Once there, type del *.* to delete font files. The system may ask you if you are sure to continue, press Y and then Enter to continue.

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As I mentioned above, that doesn't feel like a permanent solution. I'd rather try resizing the partitions first.

If someone could point me to a free tool able to do so, that'd be great.

@KevTech
So turns out MS has already changed the requirement to 200MB!

tony359 said:

If someone could point me to a free tool able to do so, that'd be great.

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Here you go.

Yes, I did mention MiniTool in my first post and why it wouldn't work.

I ran into the same issue when I attempted to resize my EFI partition (my wife's HP laptop couldn't update BIOS because of the 100MB default size). I actually had to use a combination of Minitool and Gparted (although I don't know why I couldn't use either or):

1) Boot into Gparted
2) Use Gparted to shrink C: drive by whatever you want to expand the EFI partition to. If I recall, you can select to place the created unallocated space in front of C:.
3) Move the 16MB system reserved partition behind the unallocated space...this makes the unallocated space adjacent to EFI partition where it needs to be. Unfortunately, after this Gparted failed...it would not merge the EFI partition with the unallocated space. I'm not sure why.
4) Boot into Windows and use Minitool to merge the unallocated space with the EFI partition...increasing it. I made my EFI partition 500 MB. The laptop successfully updated BIOS after.

I'm sure there is an easier/safer way to do it.

tony359 said:

Yes, I did mention MiniTool in my first post and why it wouldn't work.

Click to expand...

You can do them all at once.
Shrink, move, expand

Shrink C leaving unallocated on the left of C.

Move 16 MB to the right leaving no space between it and C.

Expand EFI

@KevTech - To shrink a system partition Minitool requires to boot from a media and do that offline. That's not in the free version. It was my point since the beginning.

@mccmw - I did that earlier on and also worked for me, with a gotcha. GParted refused to grow the EFI partition - but thankfully Windows still booted. Once in Windows, Minitool was able to do that without having to go offline. Windows update now able to continue.

Thanks @mccmw for some solid advice.

I suspect the one it's complaining about the size of is the recovery partition. You can eliminate it if you will always use a bootable recovery drive for any such operations.

tony359 said:

there is not enough space on the System Reserved partition.

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I believe you mean there is not enough space on the EFI partition.

I did this just last week. I did it offline using Minitool boot disk.
Whether necessary or not, I can't say, but I decided to play it safe and did mine in 2 steps, rebooting back into the MT boot disk each time.

1. reduced C partition leaving 400 mb free space before and 0 mb after.
deleted the 16 mb MSR partition

2. extended EFI partition from 100 mb to 500 mb leaving 16 mb free.

While the MSR partition is necessary or not, I wanted to have a standard partition scheme. So I booted to a windows install disk and used diskpart to rebuild MSR back in the remaining 16mb free space left between the EFI partition and the C partition.

tony359 said:

Hi all,

My Windows 11 refuses to upgrade because there is not enough space on the System Reserved partition.

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Please post share links:



1) Please add WMIC:





2) Run diskparinfo:







3) Run upgrade_failure_info:







4) Run tuneup_plus_log:







5) Run V2 log collector:





6) Open disk management > widen rows and columns > make sure that characters within rows are not cut off > post share links

Ghot said:

It's NOT mandatory.
MS put it there for possible future use.

Since 2021, MS hasn't used it on Win 11.
Since 2020 MS hasn't used it on Win 10.

To me... that means it doesn't need to be there.



From your Wikipedia link...




It's just a space holder.
People with partitioning software... don't NEED it.

On a side note: People with decent 3rd party backup software, don't need the Recovery partition either.
But that's another whole ball of wax.

Click to expand...

Yep totally true - on UEFI pcs only two partitions are actually required for a bootable device i.e. EFI and C drive.

The biggest mystery is why the MSR even exists when it fulfills no obvious useful function.

It's origin is kind of lost in history but here is a basic explanation for all reader who may not know the reason MS included the MSR partition in their default partition layout. Even wikipedia contributors did not really understands its origin, and you got vague "its a spaceholder" descriptions.

So here is the real reason it exists. I cannot remember where I gleaned this info but it was buried in some old MS documentation.

Essentially, on old style MBR based PCs, it was possible to store data in hidden (uncopiable) sectors of a hard drive. This was sometimes used by vendors (games especially) to hold certain identifying data to show you had a legal copy of their software. If an illegal copy was made of the software, the hidden data was not copied, and hence software knew it was an ilagal copy and would not run.

GPT (UEFI) PCs do not have such hidden sectors, so MS introduced the hidden MSR sector to effectively allow software vendors to use this to emulate the old style MBR hidden sectors. However, the advent of global internet access meant vendors changed direction, and virtually all use online verification techniques instead i.e. the hidden sector technique has been assigned to the great bitbucket in the sky.

I am unaware of the MSR partition ever being used.

It is a mystery to everybody why MS do not simply dispense with this redundant partition. My theory is there is nobody left in MS who understand its origin, and nobody has the fluffy bits to challenge the MS leadership, as the party line is it is reserved for future use but nobody can actually think how a 16 MB partition would ever be of use!

Note: under Windows 8, this partition was actually 128 MB and some old pcs upgraded from Windows 8 still have a 128 MB partition, if the user did not take steps to change it.

KevTech said:

He pointed me to another source.

UEFI/GPT-based hard drive partitions

UEFI/GPT-based hard drive partitions

learn.microsoft.com

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MSR is normally created on GPT disks in case you need to convert from a basic disk to a dynamic disk. Since almost all non-IT users never bother with dynamic disks, it's become a relatively safe suggestion to delete the MSR. Technically incorrect, but it works for most people.

glasskuter said:

tony359 said:

there is not enough space on the System Reserved partition.

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I believe you mean there is not enough space on the EFI partition.

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I mean what Microsoft is telling me!



@zbook
This is resolved now, thanks.