Block Microsoft from running experiments in the Microsoft Edge browser

[HotCakeX]

Browsers like Firefox, Chrome or Microsoft Edge come with built-in functionality to run experiments. Browser makers like Mozilla or Google may enable or disable features or changes in select browsers; this is often used to A-B test features or get early feedback on new implementations.

While most users may not even notice that experiments are running in their browsers, it happened in the past that experiments caused issues. The latest case was revealed in November when administrators from around the world reported that a Chrome experiment would crash browsers in organizations worldwide.

Negative side-effects of experiments are a problem for home users and business users alike, and it is often desirable to disable or block experiments from being downloaded and run.

Microsoft distinguishes between controlled feature rollouts and experiments in the company's new Chromium-based Microsoft Edge web browser. Both are made available to part of the user base when they start to roll out but similarities end here.

Microsoft notes:

Microsoft Edge builds have features and functionality that are still in development or are experimental. Experiments are like CFR, but the size of the user group is much smaller for testing the new concept. These features are hidden by default until the feature's rolled out or the experiment's finished. Experiment flags are used to enable and disable these features.

System administrators may use the "Control communication with the Experimentation and Configuration Service" on pro and Enterprise editions of Windows 7, 8.1 or 10 to prevent experiments in the browser.

Here is what is needed for that:

1. Get the latest Microsoft Edge policy file from the Microsoft Edge Insider website. It is likely that the policies will become available natively eventually when Edge is released and integrated in Windows.
2. Extract the file (first a cab, then a zip).
3. Open Windows  > Admx.
4. Copy the two .admx template files to C:\Windows\PolicyDefinitions\.
5. Open the language folder that matches the system language and copy the .adml files to the corresponding language folder of C:\Windows\PolicyDefinitions\
6. Open Start, type gpedit.msc and hit the Enter-key to open the Group Policy Editor. Consult this Docs page on the Microsoft website for additional scenarios, e.g. when domain controllers are used.
7. Open Computer Configuration > Administrative Templates > Microsoft Edge.
8. Open the policy "Control communication with the Experimentation and Configuration Service" policy.
9. Set the policy to Enabled.
10. Set it to either "Retrieve configurations only" or "Disable communication with the Experimentation and Configuration Service". Retrieve will download configuration payloads only, disable won't download or enable them.

The behavior of not configuring the policy differs depending on whether it is a managed or unmanaged device. Managed devices will download the configuration only while unmanaged devices will retrieve configurations and experiments.

Source

[#2]

@HotCakeX 

Nice article,

But what exactly is the different between the settings?

On a managed device "Retrieve configurations only" is the default, but what exactly does this mean?

And what is the difference with the full payload beeing downloaden?

If you follow the documentation, which states: "If you set this policy to "Retrieve configurations only" mode, only the configuration payload is delivered.", something is downloaded. But what is the impact?

And what is the impact of blocking the full communication with the Experimentation and Configuration Service?

Is there somewhere documented what is being pushed, what the impact is and what you miss out if it isn't pushed?

[#3]

Hi,
the impact should be on the browser side not receiving new features that are part of the controlled feature rollout. but if you are using stable channel of Edge, you should be fine since experiments happen in non stable channels