ms-cxh and ms-cxh-full handlers

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Update

On Windows 25H2 ms-cxh-full://foo and ms-cxh-full://0 don’t seem to work anymore.

You can still run f.ex.:

ms-cxh-full://FRX/INCLUSIVE

This will initially show the black screen and then the OOBE wizard will kick in.

When the screen is still black, you can press SHIFT-F10 and that should bring back the desktop, but once the wizard kicks in, it doesn’t work anymore. At that stage I had mixed experience with ALT-TAB still working sometimes, and switching to other applications, and sometimes just showing the preview of other tasks, but the wizard remaining on top of the screen. In such case, you can still try the WIN+R trick I described below.

  • Press WIN+R — this will open invisible Run dialog box
  • Run “taskkill /f /im UserOOBEBroker.exe” — this will terminate the “UserOOBEBroker.exe” process.
  • Run “taskkill /f /im wwahost.exe” — this will terminate the “wwahost.exe” process.

Thx to @Radkeyboard7984 for spotting the SHIFT+F10 combo and discussions about ms-cxh-full protocol.

Update

I noticed that some forums reference this post and thanks to that I realized my old post had a mistake. The CXH doesn’t stand for Cloud Experience Host, but Connected eXperience Handler!!! Thanks to garlin who explained it here.

Old Post

Another 2 bits I posted to Twitter — noticed that there is a built-in “ms-cxh” handler that was unknown to me (CXH stands for Connected eXperience Handler) and there is also its near cousin “ms-cxh-full” (which I spotted while I was looking at the Registry settings for ms-cxh).

The first one accepts a number of strings which in return launch dedicated Dialog/Wizard offering specific Windows functionality including adding new user, changing PIN, password, etc. f.ex.:

ms-cxh://SETADDNEWUSER

ms-cxh://NTHENTNGCONLY

List of available strings I found in Windows binaries:

  • ms-cxh://AADPINRESETAUTH
  • ms-cxh://AADSSPR
  • ms-cxh://AADWEBAUTH
  • ms-cxh://FRX/AAD
  • ms-cxh://FRX/INCLUSIVE
  • ms-cxh://FRX/INCLUSIVE?start=OobeProvisioningStatus
  • ms-cxh://FRX/TEAMEDITION
  • ms-cxh://FRXRDXINCLUSIVE
  • ms-cxh://MOSET/AADLOCAL
  • ms-cxh://MOSET/CONNECTTOWORK
  • ms-cxh://mosetmamconnecttowork?mode=mdm&username=%s&servername=%s
  • ms-cxh://mosetmdmconnecttowork
  • ms-cxh://MOSETMSA
  • ms-cxh://MOSETMSALOCAL
  • ms-cxh://MSACFLPINRESET
  • ms-cxh://MSACFLPINRESETSIGNIN
  • ms-cxh://MSACXSIGNINAUTHONLY
  • ms-cxh://MSACXSIGNINPINADD
  • ms-cxh://MSACXSIGNINPINRESET
  • ms-cxh://MSAPINENROLL
  • ms-cxh://MSAPINRESET
  • ms-cxh://MSARDX
  • ms-cxh://MSASSPR
  • ms-cxh://NTH
  • ms-cxh://NTH/AADRECOVERY
  • ms-cxh://NTHAADNGCFIXME
  • ms-cxh://NTHAADNGCONLY
  • ms-cxh://NTHAADNGCRESET
  • ms-cxh://NTHAADNGCRESETDESTRUCTIVE
  • ms-cxh://NTHAADNGCRESETNONDESTRUCTIVE
  • ms-cxh://NTHAADORMDM?ngc=enabled
  • ms-cxh://NTHENTNGCFIXME
  • ms-cxh://NTHENTNGCONLY
  • ms-cxh://NTHENTNGCRESET
  • ms-cxh://NTHENTNGCRESETDESTRUCTIVE
  • ms-cxh://NTHENTORMDM
  • ms-cxh://NTHENTORMDM?ngc=enabled
  • ms-cxh://NTHNGCUPSELL
  • ms-cxh://NTHPRIVACY
  • ms-cxh://RDXRACSKUINCLUSIVE
  • ms-cxh://SCOOBE
  • ms-cxh://SCOOBE%ws
  • ms-cxh://SCOOBE/UPGRADE
  • ms-cxh://SETADDLOCALONLY
  • ms-cxh://SETADDNEWUSER
  • ms-cxh://SETCHANGEPWD
  • ms-cxh://SETPHONEPAIRING
  • ms-cxh://SETPHONEPAIRING?scenarioId=SwiftKeyCloudClipboard
  • ms-cxh://setsqsalocalonly
  • ms-cxh://TSET/ADDFAMILY
  • ms-cxh://WLT
  • ms-cxh://WLTUC

When I tested ms-cxh-full – I just ran opened “ms-cxh-full://foo” from Run dialog box and it messed up the desktop of the test system by blocking any window from being visible/interactive (with some exception for Taskbar, and Taskbar previews). Interestingly, when I posted it @SoloCarry6 and @cyb3rops pointed me to some other posts on the internet where people ran “ms-cxh-full://0” and got their desktop locked. Since no one knew how to disable it, here’s a quick solution:

  • Press WIN+R — this will open invisible Run dialog box
  • Run “taskkill /f /im UserOOBEBroker.exe” — this will terminate the “UserOOBEBroker.exe” process.