Installing PowerShell module persistently for all users

Question

I'm installing a PowerShell module via Octopus Deploy onto a number of different servers. For testing purposes, I went with the guidance of Microsoft's documentation for installing PowerShell Modules.

This worked fine, but as the documentation stated, my changes would be visible only for the current session. That is, if I were to do the following:

$modulePath = [Environment]::GetEnvironmentVariable("PSModulePath", [EnvironmentVariableTarget]::Machine)
# More practically, this would be some logic to install only if not present
$modulePath += ";C:\CustomModules"
[Environment]::SetEnvironmentVariable("PSModulePath", $modulePath, [EnvironmentVariableTarget]::Machine)

When running this installer automatically on tentacle servers, future PowerShell sessions do not appear to see the newly installed modules.

How can I install a PowerShell module in a profile agnostic way so that every PowerShell session started can see it?

score 17 · Accepted Answer · answered Jan 03 '14 at 13:30

17

PowerShell can only "see" modules installed in one of the directories listed in $env:PSModulePath. Otherwise you'll have to import the module with its full path.

To make a new module visible to all users you basically have two options:

Install the module to the default system-wide module directory (C:\Windows\system32\WindowsPowerShell\v1.0\Modules).
Modify the system environment so that PSModulePath variable already contains your custom module directory (e.g. via a group policy preference).

The latter will only become effective for PowerShell sessions started after the modification was made, though.

answered Jan 03 '14 at 13:30

Ansgar Wiechers

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PowerShell 3.0 and higher auto load the modules it can find with the method above. So no need to import the modules manually or have them imported in a profile. – Lars Truijens Jan 03 '14 at 15:32
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You'd rather use the 2nd option, as https://msdn.microsoft.com/en-us/library/dd878350(v=vs.85).aspx recomends not to install user's modules in C:\Windows\system32\WindowsPowerShell\v1.0\Modules "This location is reserved for modules that ship with Windows. Do not install modules to this location." – Luiz Dec 18 '17 at 15:34

score 2 · Answer 2 · answered Jan 02 '14 at 14:51

2

This profile applies to all users and all shells.

%windir%\system32\WindowsPowerShell\v1.0\profile.ps1

answered Jan 02 '14 at 14:51

Knuckle-Dragger

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the profile in your article link only applies 'per user', the one above is machine-wide. – Knuckle-Dragger Jan 02 '14 at 14:53
Can I be assured that this will run, even if the shell is opened with `-NoProfile`? – Mike Bailey Jan 02 '14 at 14:58
I'm afraid I can't do that. I have to assume that the module will be loaded in a `-NoProfile` environment. – Mike Bailey Jan 02 '14 at 15:02

Peter Majeed · Answer 3 · 2017-03-19T04:24:23.187

After taking the steps you spelled out in your question (which I think is the general way to go), I found two ways to get the new module source recognized by Powershell:

Restart the machine. (Works every time.)
Reset the PSModulePath in each open session.
```
$env:PSModulePath=[Environment]::GetEnvironmentVariable("PSModulePath", "Machine")
```
I found this was necessary to run in both normal and elevated prompts to get this to work without restarting in each type of prompt. (See also the conversation @ Topic: PSModulePath.)

Installing PowerShell module persistently for all users

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