How to uninstall Outlook (new) on Windows 11 and prevent it from redownloading when opening the Windows Mail?

That's unfortunate.

In this case, you need to do the following:

1. New rule
2. Allow, everyone
3. Publisher
4. Select any app already installed
5. Slide that cursor to the top so that there will only be *
6. Add exception and select outlook
7. Finish

After reboot it will block installation of new Outlook permanently (occasionally it will nag at boot about an app blocked by an administrator but you can close it when it happens)

In select group leave Everyone as it is.

Choose Deny, next, Publisher, next, Use an Installed Packaged App as a Reference, choose Outlook for Windows, next, next and finish.

Now it should ask if you want to add more rules to prevent critical apps from running: click YES. If it doesn't, delete that rule you've just created.

If everything has been done correctly, you should see 4 rules: 3 allows and 1 deny (which is outlook)

It never asked if I wanted to add more rules, so nothing to click "Yes" on and so, per your instructions I deleted the rule. Also, there was only ever "One" rule - deny everyone - not 4 rules with 3 allows and 1 deny. I went through the steps twice and both ended with the same single rule - deny everyone. I don't know where I went wrong but.....

Anything else you can advise??

Thanks again for getting back as soon as you can.

Dear Marocco2,

Could you provide some clarification/explanation on a few of the steps in the App Locker instructions? For instance, under Select User or Group am I choosing Advanced and if so, then what do I choose next? Find Now? Then what - choose System? The instruction link you provided shows "Conditions" as the next step but that step is not even shown in my version it jumps right to Publisher. On that step do I choose "Use an Installed Packaged App as a Reference" or "Use a Packaged App Installer as a Reference?" In the first of the aforementioned selections I chose the first of the two and after clicking Select I was able to find Outlook for Windows in the choices. I did not select it or go any further as I wanted more clarification/instruction before proceeding. Under the second of the two it opened my File Explorer, should I choose that option and then look for Outlook for Windows that way?? Because of the version for creating packaged app rules that is on my computer I have to first choose the reference then I can set the "Scope" for the rule, at which point based on the link you provided, I am not sure which one to choose - "Applies to Specific Publisher or Applies to a Package Name."

As you can see, I need a little extra help in understanding and choosing the correct steps.

Thank you for getting back as soon as you can.

In select group leave Everyone as it is.

Choose Deny, next, Publisher, next, Use an Installed Packaged App as a Reference, choose Outlook for Windows, next, next and finish.

Now it should ask if you want to add more rules to prevent critical apps from running: click YES. If it doesn't, delete that rule you've just created.

If everything has been done correctly, you should see 4 rules: 3 allows and 1 deny (which is outlook)

Dear Marocco2,

Could you provide some clarification/explanation on a few of the steps in the App Locker instructions? For instance, under Select User or Group am I choosing Advanced and if so, then what do I choose next? Find Now? Then what - choose System? The instruction link you provided shows "Conditions" as the next step but that step is not even shown in my version it jumps right to Publisher. On that step do I choose "Use an Installed Packaged App as a Reference" or "Use a Packaged App Installer as a Reference?" In the first of the aforementioned selections I chose the first of the two and after clicking Select I was able to find Outlook for Windows in the choices. I did not select it or go any further as I wanted more clarification/instruction before proceeding. Under the second of the two it opened my File Explorer, should I choose that option and then look for Outlook for Windows that way?? Because of the version for creating packaged app rules that is on my computer I have to first choose the reference then I can set the "Scope" for the rule, at which point based on the link you provided, I am not sure which one to choose - "Applies to Specific Publisher or Applies to a Package Name."

As you can see, I need a little extra help in understanding and choosing the correct steps.

Thank you for getting back as soon as you can.

Dear Addie.C,

I did exactly what you indicated to do - opened Powershell, ran it as an Administrator, pasted all of the code you provided and hit enter, then restarted my computer to make sure the changes took place, then reopened Windows Mail and, lo and behold, New Outlook reinstalled itself again. Any other suggestions??

Thanks for trying. If you do have any other suggestions I hope to hear from you soon.

Thanks again.

In a CMD with admin, type: sc.exe config appidsvc start=auto

Then follow this guide: https://www.thewindowsclub.com/windows-8-applocker-step-by-step-guide

Select Outlook For Windows as Deny. If it ask to create other rules to allow installing and running other apps, click yes.

Reboot and now you can uninstall Outlook (new)