Yhyjyk

In AD, I create a new OU and moved my username into that OU so I can do testing with my own domain user account.

I then created a new GPO and enabled the following:

Computer Configuration > Policies > Administrative Templates > Windows Components > Store > Turn off the Store application = Enabled

I went to my local computer, connected it to the domain, logged in using my domain login details, Loaded CMD as administrator and typed

gpupdate

It displayed the following output:

C:Windows>gpupdate
Updating policy...

Computer Policy update has completed successfully.

The following warnings were encountered during computer policy processing:

The Group Policy Client Side Extension Software Installation was unable to apply one or more settings because the changes must be processed before system startup or user logon. The system will wait for Group Policy processing to finish completely before the next startup or logon for this user, and this may result in slow startup and boot performance.
User Policy update has completed successfully.

For more detailed information, review the event log or run GPRESULT /H GPReport.html from the command line to access information about Group Policy results.


C:Windows>

I tried loading Microsoft Store, but it still loads.

I then tried the following command:

gpupdate /force

The following output was displayed:

C:Windows>gpupdate /force
Updating policy...

Computer Policy update has completed successfully.

The following warnings were encountered during computer policy processing:

The Group Policy Client Side Extension Software Installation was unable to apply one or more settings because the changes must be processed before system startup or user logon. The system will wait for Group Policy processing to finish completely before the next startup or logon for this user, and this may result in slow startup and boot performance.
User Policy update has completed successfully.

For more detailed information, review the event log or run GPRESULT /H GPReport.html from the command line to access information about Group Policy results.

Certain Computer policies are enabled that can only run during startup.

OK to restart? (Y/N)Y
Restarting the computer...
..

C:Windows>

After the computer has restarted, it still loads Microsoft Store.

I have checked GPReport.html, and I can't see any mention of the GPO to disable the Microsoft Store.

Any ideas why this is not working?

Environment details:

Client computer on domain:

• Windows 10 Enterprise (Desktop client computers connected to the
  domain)

On domain servers:

• Exchange 2013


• Active Directory 6.3.9xx

In AD, I create a new OU and moved my username into that OU so I can
do testing with my own domain user account.

You can't link a Computer Setting GPO to a User account, you must link it to a Computer Account.

I have checked GPReport.html, and I can't see any mention of the GPO
to disable the Microsoft Store.

As a result, GPResult don't show the GPO linked, it's normal.

Make sure the GPO is enforced to the correct OU where the computer account is to have the settings applied.

For me it's a simple error from there. Why ? because if it would be a security group error or a WMI filter, the GPO would be listed inside GPResult, but with an access denied error.