what partitions does windows automatically create during instalation

128 MSR partition was always the standard, now it appears they allow 16MB MSR

fdegrove said:

Hi,

On all the EFI/GPT clean installs I did so far the partition scheme turned out like this. Ignoring partition #5 which was created by myself afterwards.
I possibly also moved the Recovery partition so it sits in front of the C:\ drive in case I need to expand that one.
Note the 128Mb partition which I suppose is the MSR partition created when a drive is converted to GPT.

Question is, why 128 Mb and not 16Mb ? Assuming this is the same MSR partition mentioned by you guys.

TIA,

128 MB MSR was in WIndows 8. Windows 10 MSR is 16 MB. See last bullet point under "What's New in Windows 10" on this page: https://msdn.microsoft.com/en-us/lib...(v=vs.85).aspx

On all the EFI/GPT clean installs I did so far the partition scheme turned out like this. Ignoring partition #5 which was created by myself afterwards.
I possibly also moved the Recovery partition so it sits in front of the C:\ drive in case I need to expand that one.
Note the 128Mb partition which I suppose is the MSR partition created when a drive is converted to GPT.

Question is, why 128 Mb and not 16Mb ? Assuming this is the same MSR partition mentioned by you guys.

I always look at the partition scheme on every build of Windows 10. In the earlier build 10125 and prior. MS has been adjusting those partitions until build 10135 and I do have backup of those builds.

Up til build 10125, the partition scheme was always the same as for Windows 8.1 and they made it permanent (450, 100, 16 and C drive for GPT disk)from build 10135 because more space needed to store WinRE.wim. So If you upgraded from the early build of Windows 10, you'll get that 128MB MSR.

Now, if you do a fresh install of the current build (10586), you'll get 16MB MSR. I guess MS figures that it does not need that much space for MSR partition. However, on a regular (non Windows OS) GPT data disk, the MSR partition still is 128MB and is the first partition of the disk. You can change the partition scheme as shown in this thread using Macrium:
Solved Help With Partition Management - Windows 10 Forums

topgundcp said:

.... I guess MS figures that it does not need that much space for MSR partition. ...

That guess might go along with this: "We recommend adding a separate partition for the Windows Recovery Environment (Windows RE) at the end of the hard drive. With this partition order, if future updates require adding to or replacing the Windows RE tools partition, Windows will be able to manage the partition size automatically." [excerpted from link in my prior post]

By "go along with", I mean maybe MS isn't willing to commit to 128 MB MSR (already whacked down to 16 MB now) being enough for "the future" expansion of WinRE and they're dodging this by suggesting WinRE be placed at the end, having left behind a "token" 16 MB MSR.

they're dodging this by suggesting WinRE be placed at the end

This allows future updates to Windows RE to grow the Windows RE partition by shrinking the Windows partition.

If you go back and look at any upgrade partition shceme - you will see the OEM winre partition before the windows partition..
And the upgrade winre right after the windows partition.. the reason is because you shrink from the right,, so leaving winre far right allows for shrinkage of C to expand RE..

Has nothing to do with MSR partition..

Hi,

First of all , thanks for all the replies.

We have to be careful when referring to a Recovery partition, since there are two types. We also have to acknowledge configurations by OEMs can be different from a user install.

As far as I'm concerned, nothing to do with OEM stuff.
All my machines were upgrade installs converted into fresh installs on a "clean" disk afterwards.
I can't recall exactly when I started using W10, I guess I just did when they offered the free upgrade but I'm willing to start afresh with any current version just to find out.

The only thing that triggered my curiosity is that MS talks about a 16Mb MSR partition whilst I've never seen any of those on my machines. Not that it really matters, just curious that's all.
Just to be clear, I'm talking setup doing its thing. Not the user sysprepping a machine.

Cheers,

EDIT: Apologies to TS. I feel I've thread-jacked your thread for the sake of a 16Mb question.........

Kyhi said:

This allows future updates to Windows RE to grow the Windows RE partition by shrinking the Windows partition.

If you go back and look at any upgrade partition shceme - you will see the OEM winre partition before the windows partition..
And the upgrade winre right after the windows partition.. the reason is because you shrink from the right,, so leaving winre far right allows for shrinkage of C to expand RE..

Has nothing to do with MSR partition..

Acknowledged, @Kyhi . I confess I grabbed that excerpt and interpreted it out of context (i.e., I missed the key word "separate" for this WinRE they talk about - and thank you @Saltgrass in helping me realize that). I was on a path of interpreting MSR for "future use" to mean in case they wanted to increase the size of the WinRE (the one at front of the disk) in the future. Now I'm realizing that "they" includes OEMs (as opposed to only MS). I had thought perhaps the shift from 128 MB MSR to 16 MB MSR in the Win10 builds evolution (noted by topgundcp) was directly related to the growth of the WinRE from former size to the current 450 MB and was trying to rationalize it that way in response to fdegrove's question.

Love these discussions and thank you guys for letting me reveal my ignorance from time to time - it's about the best way I learn, through my mistakes.