KB5004123 CU Windows 10 Insider Preview Dev Build 21390.2025 - June 14 Insider

f14tomcat said:

Re-install, clean install. Not necessarily reformat the drive, although some do because they want to. It's sufficient to delete the partition and supporting partitions on the clean install. Opting out of Insider does not imply a reformat nor is that stated anywhere I know of. If MS says you must reformat your drive to Opt Out, I would like to see the Microsoft Documentation that states that.

There is no published way of getting out of the Dev channel without a re-install as it is now never on the same build as any other channel.

kado897 said:

There is no published way of getting out of the Dev channel without a re-install as it is now never on the same build as any other channel.

I know that. I said reformat, not reinstall. No Documentation that says one must reformat.

f14tomcat said:

I know that. I said reformat, not reinstall. No Documentation that says one must reformat.

Agreed. I've changed a computer in the Dev channel as a replacement for an older one and the re-install worked fine. If having an issue I prefer wiping out the partitions on a drive then let Windows do the full install, has always assured getting rid of all existing problems.

Berton said:

Agreed. I've changed a computer in the Dev channel as a replacement for an older one and the re-install worked fine. If having an issue I prefer wiping out the partitions on a drive then let Windows do the full install, has always assured getting rid of all existing problems.

Doesn't reinstall actually format at least C: and relevant partitions ?

f14tomcat said:

I know that. I said reformat, not reinstall. No Documentation that says one must reformat.

Yep, but that's what some people call a re-install.

CountMike said:

Doesn't reinstall actually format at least C: and relevant partitions ?

Not always, saving files and apps choice may not.

Berton said:

Not always, saving files and apps choice may not.

Saving files and apps is only available on a repair install. You can't use a repair install to get out of the Dev Channel.

Simple answer to get out of Insider Development, you start over. Over, as in you save nothing in the process. You cannot go backwards in an update of any kind whatever you call it. Saving your data and other whatevers before hand is just simple common sense.

And all the foregoing is why the joining one of the Technical Preview choices, later named Insider Preview, carried advise/warnings not to use it on an only computer or a production computer because there would always be changes. To that end I have the IP Dev on 2 older computers not used for anything except testing or verifying whether programs will have issues in future releases, one I had to install an Add-in Video card due to no support for the onboard/built-in video adapter. And it helps to keep in my mind I don't have to be frustrated when something goes wrong and I can't complete required work, get the job done on an RTM machine, try to figure out the problem with the IP later.