Trouble finding W10 21H2 ISO


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Hi everyone, new to the forum. Red up on all the awesome guides by Hellbovine aswell as some threads on the forum to prepare for a custom ISO.

I'm having a bit of trouble to find the 21H2 for download though, Rufus says to try again later. If I choose the 22H2 version, its available.
Question is, seeing as how 21H2 is reaching end of life within short, is 22H2 the only option now? And how does this work if I follow the Optimized Image guide?
I would only trust Rufus (Fido.ps1) since it downloads from MS servers, but I suppose you could risk using ISO files from
There's an open bug confirming that requests for non-current ISO's are being blocked.
...seeing as how 21H2 is reaching end of life within short, is 22H2 the only option now? And how does this work if I follow the Optimized Image guide?
22H2 can be used with my guides, and all/most of the tweaks will still work. The main reason I chose 21H2 is because 22H2 had too many bugs, and after 6 months there's still issues remaining for Microsoft to fix. 21H2 on the other hand is stable, had no known issues, and is also what LTSC 2021 uses, so it was a good version to use as a base.

21H2 reaching end of life doesn't really matter until popular 3rd party software start dropping support for it, but that will be years from now and by then the guides will likely use a newer build anyway.

There are other reasons for not using 22H2, but those are more complex:
Besides all of the officially known issues, when I tested 22H2 I discovered an undocumented task scheduler bug (link) that renders the 22H2 build currently hosted on Microsoft's website too broken to be usable, if you do not install the Windows updates that were released later. The main problem is that many of us hardcore tweaking enthusiasts pause/disable/uninstall Windows update because it can install ads, bloat, resets tweaks to defaults, restores uninstalled components, and add new bugs as we've seen with 22H2.

Microsoft does not refresh their media creation tool or website with updated ISO builds, except for once per year, and so we are forced to wait until 23H2 releases to download that (if it isn't buggy) and stick with an older version like 21H2 in the meantime. Even then, Microsoft recently announced that 23H2 will not be made available for Windows 10, so all we can do is hope they still release an updated build at the end of this year, even though the version won't change.

I don't know how I want to address all of this yet, because I had already settled on just waiting for 23H2 to update the guides, but now that's uncertain. There's a lot of options available to address this 22H2 task scheduler bug, but I haven't worked through them and evaluated which approach is best, within the premise of an easy-to-use guide.

I'm open to suggestions on how to address this in the guide, but it has to be clean, simple, and easy for inexperienced users to follow, I don't want to have to write a bunch of extra steps, such as by having people use 22H2 and then doing Windows updates through NTLite because updates can cause problems, and I haven't seen anything about 22H2 that excites me. Plus, it's all too much for the masses to follow, the guide is long enough already and needs to be shortened, not made longer. If Microsoft would just fix their crap I could go update the guides.

To summarize, Microsoft is really screwing up this year:
- 22H2 on both Windows 10 and Windows 11 was too buggy to release and still has issues
- Microsoft is blocking people from downloading older Windows 10/11 versions right now
- Windows 10 will not get a 23H2 update (link) which means newer builds may not be posted
- The new SecureBoot exploit (link) will take months to address and will affect the future
- Older Windows (W7) are no longer an option because they can't run popular software now
- Windows 11 in my testing had lower performance in some areas and higher DPC latency
- Windows 11 is actively evolving which makes it buggier/unstable, and more work to tweak
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I tried several other tools/sites and many of them have the same problem as Rufus, so it's definitely Microsoft trying to block the download of older versions, or something of that nature. Only 22H2 for both W10 and W11 can be downloaded now.

AveYo's MCT wrapper is a tool that still works though, and it let me download W10 21H2 (link). Basically it takes the official Media Creation Tool and then modifies it to allow for more options.

Questions about the wrapper tool:
I have some reservations about this tool because I don't know how to verify the integrity of all the files. I checked the hash of the ISO from this tool and it doesn't match the one I downloaded from Microsoft, but that is likely because the Media Creation Tool uses ESD compression, while Rufus and the Microsoft website offer the non-ESD ISO.

Another concern I have is that the wrapper may be adding some registry keys into the image, and in addition to that this tool also adds a file called, "auto.bat" into the ISO which appears to have additional registry keys being added too. I don't understand all the code though, so I need someone else to comment on that.

I did use a file diffing program and compared all of the files inside AveYo's ISO to the Microsoft website ISO, and they seem to be identical, but I also don't know if it can properly compare all of these different kinds of non-standard files, since most of these programs are meant for things like .txt file comparisons instead.

To use the wrapper tool, copy all the text from here (link) and then paste it into a regular Windows notepad. Now go to "save as" and label it "MediaCreationTool.bat" without quotes, then in the "Save as type" bar at the very bottom change it from "Text Documents" into "All Files" and save it. The icon of the file on your desktop or wherever you saved it to will now change into a cogwheel, meaning it is a .bat file. Run the file then select version 21H2 and also the "Auto ISO" option and it will begin downloading.
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Reading up on your research about 22H2, I'd really like to avoid it, but if MS are blocking downloads of older versions and its recommended to only download directly from them, where is MediaCreationTool taking its ISO from? I red your description above and you mention that it adds the "auto.bat" file. Would you say that this ISO is still safe to use then?
I looked into the wrapper more and there may be some better options:

1) Use the official URL to download the 21H2 Media Creation Tool directly from Microsoft (link). I tried this and the resulting files were unmodified, however I don't think it's quite the same build that Microsoft offered in the past because there were a few differences in about 8 of the ~900 files. There seems to be a "refresh" .cab file (link) that is required to reconfigure things, but I don't know how to use it.

2) According to the comments in the code, if we select "MCT Defaults" instead of "Auto ISO" it should result in a clean image without extra tweaks. Alternatively, if you rename the bat file to "def MediaCreationTool.bat" without quotes it should create unmodified files too when it is ran. I haven't tried this yet, since the downloading of files and then conversion from ESD to WIM is all so time consuming.

It looks like the reason this wrapper works while all the other tools/sites do not, is because the Media Creation Tool uses different URL links, and Microsoft hasn't deleted/blocked those yet. It's way past bedtime for me though, I'll have to look into this more tommorow, and hopefully some other people that are more skilled in this area help tackle this thread too because the Media Creation Tool and this .bat file are unfamiliar to me.
Ok, so I used both the 21H2 media creation tool aswell as MCT Defaults along with MediaCreationTool.bat. The results were different.

The USB created with MediaCreationTool.bat "MCT Defaults" is a total of 4,18 GB (4 491 083 776 byte) with 905 files while the MS provided 21H2 creation tool generates a USB with 4,36 GB (4 689 543 168 byte) with 907 files.
I'm excited to get started with the Custom ISO, but still uncertain which one to use. Can I trust the one created with MediaCreationTool.bat?
I looked into this a lot more today, and until the dust settles from this recent change by Microsoft, I think the best solution is to use AveYo's MCT wrapper tool and be sure to choose the "21H2" and "MCT Defaults" options.

I used various methods to compare the different sources, and the notable results are below:
1) Microsoft's 21H2 ISO from their website with the user-agent trick (or using Rufus):
Windows 10 Home
14,761,526,157 bytes
Version : 10.0.19044
ServicePack Build : 1288
Created : 10/6/2021 - 7:09:22 AM

2) AveYo's MCT wrapper using the "21H2" and "MCT Defaults" options:
Equivalent to #1

3) Using the direct URL to Microsoft for the 21H2 Media Creation Tool:
Windows 10 Home
15,073,784,315 bytes
Version : 10.0.19045
ServicePack Build : 2965
Created : 5/5/2023 - 5:37:37 AM

I also went to Microsoft's website and downloaded the 22H2 Media Creation Tool and the 22H2 ISO using the browser-agent trick, then did all these tests on those too, and the results were similar in that the Media Creation Tool has some slight differences in a few files compared to the ISO download, so that part of it seems legit.

I suspect Microsoft may have pulled all of the ISO downloads for previous versions because of the SecureBoot announcement. Maybe after enough pressure (once the masses realize things like Rufus don't work anymore) Microsoft may make older ISO versions available again.

In summary, Microsoft is updating the builds for older versions when you use their Media Creation Tool directly. This means that only AveYo's MCT wrapper will give you the same builds that Microsoft originally uploaded to their website in previous years. When Rufus was working it was also pulling the original builds, and not recently modified ones.

When converting the ESD download in NTLite, load the edition you want (Home for example), then it will give a prompt about deleting the others, choose the option that gets rid of the extras and when it's done converting to WIM you will have a clean base image. Exit NTLite when it's finished, then backup those files in case Microsoft deletes these too. Plus, this saves you from downloading/converting again if you make a new image from scratch.
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Why bother with AveYo's wrapper if you don't intend to use his image mod tweaks? He's calling MCT, using UI events to walk through the prompts and then mods the saved ISO.

If you're focused on grabbing the correct MCT version (because MS removed the older ones), then download:

Bottom line: MCT, UUP dump more or less do the same things. MCT downloads a product CAB, which extracts a XML list of retail editions and picks them to download. UUP dump re-assembles its ESD using UUP files (hence the name).

When they're both done, each creates a wrapper ISO. MCT is self-contained and doesn't need ADK or oscdimg. UUP downloads its own toolkit to perform the same work. There are minor differences in the ISO "shell", but the important files are boot.wim & install.wim/esd. Most of the non-core files are used by the in-place upgrade version of Setup.exe.

When you integrate Dynamic Update for Windows Setup, a number of these ISO files get replaced. Therefore a MCT, UUP dump or the original ISO are all slightly different, and compression varies.

Last night, I tweaked Michael Niehaus' MediaTool script, which is yet another media creation tool. He does the same work extracting a XML and downloading a specific ESD. This one isn't a GUI, but you can pull any of the retail builds listed in the XML. It does require installing the ADK to get support for the boot files and oscdimg.

Where UUPudump and and MediaTool excel is pulling single edition images. I hate MCT giving me so many extra editions that are never used.
If you're focused on grabbing the correct MCT version (because MS removed the older ones), then download:
This doesn't work for me, I explained that in my posts. The URL I used and discussed was this one:

It produces the results I listed in my last post, it does not give you a 21H2 image, it gives you a 22H2 image, specifically Version : 10.0.19045, ServicePack Build : 2965.

I don't know how to use uudump, that sites doesn't make sense to me. I have never had to deal with this junk before, it's always been as simple as downloading an ISO from Microsoft, there was never a need for me to complicate things by trying to mess with anything else. So if you can explain what I'm missing on how to make a W10 21H2 ISO from uudump I'm all ears.
looks like microsoft is about to release updated isos for windows 10 and 11
This could be promising, I can give 22H2 another shot again and see how it has progressed. Ideally I would like all the guides to be updated for 22H2, it was just too buggy initially.
This doesn't work for me, I explained that in my posts. The URL I used and discussed was this one:

It produces the results I listed in my last post, it does not give you a 21H2 image, it gives you a 22H2 image, specifically Version : 10.0.19045, ServicePack Build : 2965.
Here's a relatively non-scary script (ignore the WimgApi code declarations). Jump to the bottom and change the strings.


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Thanks, I'll check this out, it does look like it's a lot easier to read so I appreciate that from a transparency point of view.
Older MCT versions will still download latest version's product CAB (e.g. MediaCreationTool1803.exe will download 19045.2965) which may not work correctly

if you want old version with its own MCT, then download its product CAB, rename it to and place it in the same folder with MCT, then start it from command line: MediaCreationTool.exe /Selfhost
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I found that the cab has to be named products with an "s" on the end, or the tool fails to run in selfhost mode. Also, yeah the pastebin is the wrong build, the link I posted earlier is the right cab file for .1288.

I'm almost finished with a small guide that will take inexperienced users through the whole process. It uses a simple batch file of just 2 commands versus 1500 lines from all these others. You should still post your wrapper though because it's likely something that advanced people would be interested in.
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How to use Microsoft's official Media Creation Tool to obtain an original Windows 10 21H2 (November 2021) build.

For people being sent here, the reason this guide is necessary is because Microsoft started deleting all the links to their older operating systems and versions. This affected their own website, but also affects other third party sites and tools too. As of right now, only the latest versions of Windows 8.1, 10, and 11 are available, and I'm confident 8.1 will end up being deleted by next year as well.

1A) Media Creation Tool:

1B) Configuration File:

1C) Batch File:
cd /d %~dp0
start MediaCreationTool21H2.exe /selfhost

Note: to create the batch file, open Windows notepad and copy the two lines above into it, go to "save as" and label it "START.bat" without quotes, then in the "Save as type" bar at the very bottom change it from "Text Documents" into "All Files" then save it, and exit notepad.

2A) Make a new folder on the desktop named "MCT" without quotes, then copy the files from step 1 into it.

2B) Rename the products_Win10_20211115 file to "products" without quotes.

2C) Make a new folder on the desktop named "21H2" without quotes, it will be used later.

3A) Inside the "MCT" folder, right-click on the START file and select "Run as administrator" to begin.

3B) Wait for the program to finish loading and then click "Accept" at this prompt.

3C) Click "Create installation media" and then click "Next" at this prompt.

3D) Adjust the language/edition/architecture if needed and then click "Next" at this prompt.

3E) Select the "ISO file" option and click "Next" at this prompt.

3F) Save the ISO to your desktop and it will begin downloading.

3G) When the download is done, ignore the "burn to DVD" option and click "Finish" at this prompt.

4A) Go to where you saved the ISO and right-click on the "Windows" file and click "Mount" to open it.

4B) Press ctrl+a to select all files, press ctrl+c to copy all files, then paste them into the "21H2" folder.

4C) After the file transfer is done, right-click on the "ESD-ISO" drive and click "Eject" to unmount it.

4D) The "Windows" ISO file can be deleted now, and you should exit out of all open folders.

4E) Run NTLite, click "Add" from the top left, choose "Image directory" and select the "21H2" folder.

4F) Right-click on "Windows 10 Home" (or Pro) and select "Load" and then click "OK" at the prompt.

4G) At the next prompt asking to "Keep only" choose "Yes" to eliminate the extra editions.

4H) After the conversion is done, wait for it to automatically reload the image.

4I) After the image is loaded, click "Apply" from the left menu and select "Process" at the top left.

4J) After the processing is done, exit NTLite, then backup the entire "21H2" folder to a safe location.

Note: before you get started using NTLite to tweak your image, never use the backup files, always have NTLite point to a copy instead of editing the original. This way, if Microsoft deletes/blocks the downloads in the future, or if you mess up your image and need to start fresh, you will have a clean backup that is already downloaded and converted to make a copy from, rather than going through all of these steps again.

I do not have plans to add this into the "Guides" section of the forum yet because the situation is new and evolving, with much of the issues originating from the BlackLotus and SecureBoot issues that are going to take a very long time to fully resolve (into the year 2024). Also, Windows version 23H2 will release at the end of the year and we do not know how Windows 10 will be treated in that scenario--will it get an updated ISO on Microsoft's website? It's all a big waiting game right now, we just need to see how things develop in the near future.
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I'll save you the work of Steps 1. thru 3B.
Please specify a MCT version:
MCTWrapper.bat W10_21H2
MCTWrapper.bat W10_21H2 /Retail /MediaLangCode en-US /MediaArch x64 /MediaEdition Enterprise

This script downloads the right MediaCreationTool.exe (if the file isn't found), and runs self-hosted. You can pass along MCT command line options to skip any language, architecture and edition prompts. Multiple copies of MCT can exist side by side, because the script knows where to find the correct

If you're asked for a product key, use one of the generic KMS client keys. Key Management Services (KMS) client activation and product keys
From the above example, Enterprise edition requires NPPR9-FWDCX-D2C8J-H872K-2YT43.

Create a local ISO file (since you're going to use NTLite to edit the image). Continue to Step 3G.

MS removed 1803 from download, switched to the Internet Archive's backup.


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