Uninstall PowerShell from Windows Server 2012; And get it back

A couple of days ago I was doing a deployment. It was one of those days where nothing seemed to work. Everyone is familiar with them and probably detest them as much as I do: the type of non-productive days where nothing productive gets done.

I actually had a lot of setbacks. Firewalls being too restrictive. Network traffic not routed correctly. Group Policy Objects (GPOs) magically breaking my clients Active Directory connections. And then, instead of throwing my laptop, I wanted to start from scratch with the server I was working on at that particular moment.

I got a little more than I bargained for. So in my infuriated state I decided it was a good idea to remove all features and roles from the server. I opened server manager, choose to remove roles and features, and deselected all options, not really paying attention to what I was doing.

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The Server Manager gave me a summary of the jobs at hand, but of course I did not read it. I clicked the close button and went for a cup of coffee.

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When I came back the server innocently asked me to reboot it. Suggesting that was needed to complete the task I had assigned. Giving it no secondary thought I gave the command to shutdown forced and reboot immediately.

When it came back up, I logged in and was happily greeted by a command prompt shell. Thinking I accidentally uninstalled the graphical user interface from Windows Server 2012, I wasn’t worried for a second. So I gave command to start PowerShell and was presented with the following error message.

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Oops…

What did I just do? Uninstall everything. And I really mean everything. Turns out that unchecking everything includes .NET 4.5 and thus removing everything, leaves your server quite useless. Something like a Windows 2008 Server Core installation.

Then I remembered “Deployment Image Servicing and Management”. Usually referred to as DISM. First, I checked what features where available. I put the output to a text file because otherwise it wouldn’t be really readable.

DISM /Online /Get-Features > features.txt

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As you can see, almost everything is disabled. This gives new meaning to “build from scratch”.

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then I used the following command to install PowerShell again:

DISM /Online /Enable-Feature:MicrosoftWindowsPowerShell /all

Notice the /all switch at the end of the command. This tells DISM to install the prerequisites as well.

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The PowerShell command now works again.

To the GUI

Still there is no Graphical User Interface. And for the sake of this blog I used DISM to install that as well:

DISM /Online /Enable-Feature:Server-GUI-Shell /all

This will ask for a reboot.

Then the server will install the GUI again and will be manageable by IT Pros who don’t like the command line that much.

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And after this operation completes and you log in, the GUI is back.

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Then I went on with the deployment as planned and this server is now running the Remote Access Role and configured to manage DirectAccess for a couple of Windows 8 clients. It’s running this without any problems.

To Sum up

You can remove PowerShell from Windows Server 2012 by using the Server Manager and selecting the Remove Roles and Features option.

Afterwards you will boot into a Command Prompt where PowerShell will not work because it is not enabled.

I used the following DISM commands to enable the feature again:

DISM /Online /Enable-Feature:MicrosoftWindowsPowerShell /all

With PowerShell enabled, it should be a breeze to fix the server some more.

Keep in mind that this server still had its source files. There are methods to add or remove the source files.

Concluding

Windows Server 2012 is very modular. Almost everything is removable. There might be scenarios where this can be useful. It might just want to be something to keep in mind.