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HEFong-5144 avatar image
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HEFong-5144 asked jiayaozhu-MSFT answered

Namespace Separation registry inquiry

Hi, I hope this is the right place to ask...

Is there any documentation, known reasons, or use cases as to why these particular registry entries exist:
\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\NamespaceSeparation

DWORD AppcontainerUserSeparation
DWORD InteractiveUserSeparation

by default, they are both set at zero.

The names themselves imply some sort of barrier or security setting but I do not want to make any assumptions between (some namespaces? but where or is this farfetched).

Testing them seems to indicate that if I enable (i.e. set to 1) InteractiveUserSeparation my graphics and general user experience completely breaks (errors on disk access and black background screen etc...). I wish I had a screenshot. (on restart)

However, enabling AppContainerUserSeparation does not (so far) seem to cause any errors or any applications to break so far.
Running Process Explorer doesn't yield much information as most of the Windows store apps I have seem to be in working shape still even after the restart.
I do not know where to start looking either as a preliminary search on the web fares me nothing.

If there is no value in having it (from any standpoint) enabled, I see fair point to leave it untouched.

Forgive my curiosity in advance.
Thanks for all your help.

windows-10-generalwindows-sysinternals-general
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jiayaozhu-MSFT avatar image
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jiayaozhu-MSFT answered

Hi,

Thank you for your posting!

Based on your descriptions, I suppose you would like to know why your computer is installed namespace separation service and what is namespace separation's functions.

There are many reasons why you have namespace separation (p.s. like @SSengupta-4080 said, isolation and separation are identical), such as the docker configuration, the use of appcontainer, etc. However, you will not be panic after you get a brief insight for namespace isolation.

-What is namespace isolation/separation and how does it work?
The user namespace allows a process to have root privileges within the namespace, without giving it that access to processes outside of the namespace. Isolating a process by the IPC namespace gives it its own interprocess communication resources, for example, System V IPC and POSIX messages.

More information can be found in this article:
https://www.toptal.com/linux/separation-anxiety-isolating-your-system-with-linux-namespaces

Please note: Information posted in the given link is hosted by a third party. Microsoft does not guarantee the accuracy and effectiveness of information.

And this video:
https://www.youtube.com/watch?v=mlm4OBNwJPQ

Please note: Information posted in the given link is hosted by a third party. Microsoft does not guarantee the accuracy and effectiveness of information.

-What are these two items:
DWORD AppcontainerUserSeparation
DWORD InteractiveUserSeparation

As I have explained before, namespace isolation is used to separate different processes, otherwise system corruption may occur on your computer. However, as you can see in the introduction, namespace isolation service belongs to Linux and is firstly introduced in Windows Server 2016. So, your win 10 system may not allow this service applicable to the whole system, to some extent. In Windows, windows container and Hyper-V container are enabled so you can see there is no error message occur when you enable AppcontainerUserSeparation. The article is just the one that @SSengupta-4080 has introduced:

https://docs.microsoft.com/en-us/windows/win32/secauthz/appcontainer-isolation#:~:text=The%20AppContainer%20environment%20creates%20an,application%20cannot%20impersonate%20the%20user.

Thank you for your support!

Best regards
Joan


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SSengupta-4080 avatar image
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SSengupta-4080 answered

You are right, I have checked my system's registry.

I have got a reference on AppContainer Isolation

Seems isolation and seperation are identical.

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