Windows 10 v21H1 will not update to v21H2 and other issues

Windows update never trys to install the latest version to 21H2, so I tried Windows 10 update assistant. It does not install 21H2 and ends up saying "You can't install Windows on a USB flash drive using Setup". There is no flash drive installed when running Windows 10 update assistant. Also get error code: 0xc1900201.

Windows update works fine otherwise, it just updated to latest kb5008212 for 21H1 for x64 systems.

Also tried downloading the v21H2 update and manually installing, but that did not work. Not so sure I had the right update, it was v21H2 kb5007253 for x64 systems. Also tried v21H2 kb5008212 for x64 systems, but it says I already have it installed.

Other issues I have noticed are: 1) System restore no longer working. 2) Windows memory diagnostics not working.
I have no BSODs or lockups, system runs fine otherwise.
I'm thinking of reinstalling windows 10 (does not meet requirements for 11) if there is not an easy fix to these issues.
Thank you in advance for any help you can provide.

If Windows 10's auto update is not offering updates fast enough for you, you can click on "Check for Updates" in settings. Even then it does not offer all possible updates at one time. After each set of updates is downloaded and installed you just click on "Check for Updates" again. You repeat that until it says there are no more updates.

I just got done doing than on an old computer I built in 2009. Last week after doing a bunch updates it ended by updating to 21H1. This week I did the same thing. This time it downloaded a bunch of updates including 21H2.

The question is did you try to manually click on "Check for Updates"? If you had you might have been offered 21H2.

Bree said:

Those are not the right updates. To update to 21H2 you want the small 21H2 Enablement Package KB5003791. This installs like a cumulative update. Thiis should be offered to you in Windows Update, but not all systems have seen it offered yet. MS are still rolling out 21H2 as a phased rollout, The last of my system to see it offered only got it this Tuesday.

KB5007186 Windows 10 2004 19041.1348, 20H2 19042.1348, 21H1 19043.1348

That worked! Thanks!

radman3d said:

Windows update never trys to install the latest version to 21H2, so I tried Windows 10 update assistant. It does not install 21H2 and ends up saying "You can't install Windows on a USB flash drive using Setup".

For future problems, change the incorrectly set registry entry that Windows is installed on a USB stick with the following command in the command prompt as admin:
reg add HKLM\SYSTEM\CurrentControlSet\Control /v PortableOperatingSystem /t REG_DWORD /d 0

After a restart you should not get the message again if you want to perform an in-place upgrade with the update assistant or with a ISO.