Create media for automated unattended install of Windows 10  

@Kari,

In that article that you had linked to (HDD and SSD capacity – GiB or GB, TiB or TB? – Win10.Guru), I noticed that you are allocating 128 MiB to the MSR partition in your example. In that article you reference the Microsoft documentation detailing the partition requirements. That documentation still recommends 16 MiB (although they call it MB).

I'm just wondering if the 128 MiB you are using in the example is a preference or if there is some recommendation to use this size rather than the 16 MiB that I am accustomed to.

EDIT:

Kari, I also just saw this article of yours:

Thank you, Microsoft – An Important Change in Windows Setup – Win10.Guru

Does the fact that 20H1 creates the WinRE partition later in setup mean that in an answer file I only need to create the EFI, MSR, and Windows partitions? If I understand your article correctly, then I assume that this would be the case and that would really be good news.

EDIT #2:

I pulled down Windows 20H1 (2004) prerelease ISO and tried installing with a modified answer file. The answer file is the same as for any previous version of Windows except that the WinRE is not specified and the other partition numbers are changed so that the EFI part is #1, MSR is #2, Windows is #3. Unfortuntely, a WinRE partition is not created automatically as I had hoped. So at this point, it looks like one has to manually calculate the Windows part size so that enough space can be left for the WinRE part at the end. That's ugly.

hsehestedt said:

I'm just wondering if the 128 MiB you are using in the example is a preference or if there is some recommendation to use this size rather than the 16 MiB that I am accustomed to.

I am today using 128 MB MSR partitions in all my deployments and installs. Microsoft clearly tells that 16 MB is the minimum size, and as far as I know, using 16 MB does not cause any issues.

I tried desperately find the online webcast recording from just after Windows 10 was launched, in which I heard a Microsoft engineer recommended using 128 MB for MSR partition, I am relatively sure I saved it. As I remember it, the point was that although the partition is at the moment not used, it having no function, it will become an important part of Windows setup in "in the future as we are thinking today".

In any case, I cannot find it, and I cannot find anything else supporting this. As long as Microsoft does not officially announce new partitioning guidelines, you can safely allocate only 16 MB for Microsoft Reserved (MSR) partition.

hsehestedt said:

Does the fact that 20H1 creates the WinRE partition later in setup mean that in an answer file I only need to create the EFI, MSR, and Windows partitions? If I understand your article correctly, then I assume that this would be the case and that would really be good news.

I assumed so, when in installing build 19023 back in November 2019 I noticed that Windows Setup had changed the way automatic partitioning works. Unfortunately, I was wrong assuming that, so the answer to your question is no.

It has always been possible to only create EFI, MSR and Windows partitions in answer file, and completely forget the WinRE partition. It is not required for Windows to work. However, doing it, recovery options are not available, so it can't be recommended.

Of course, after deployment or clean install, you can always shrink Windows partition and manually create WinRE partition and recovery environment, but this is not a practical approach.

I am repeating myself, but I really want to emphasize this: when deploying the same image to different hardware, on hard disks on different sizes, and when correct partitioning is important, use MDT!

Kari

hsehestedt said:

Sure enough, my questions were in the last posting on your MDT tutorial thread. I never did get that resolved. I'll try again today or over the weekend and post more details on what I was encountering.

I think I did not reply to you because of the last edit you made to your post:


If I had misunderstood that, I sincerely apologize. In any case, you import your custom WIM as operating system to MDT (Step 3.4 in MDT tutorial):


Kari

hsehestedt said:

In the meantime I've started the tutorial again and I'm already running into a problem. It must be something dumb I'm doing so I'll work past that and let you know how I do.

Please post in MDT tutorial thread, I am sure we can resolve your issues.

Kari