windows - Powershell Add System Variable

Question

I am Trying To add a System Variable here using PowerShell:

I have tried both ways using

$env:MyTestVariable = "My test variable."

and

[Environment]::SetEnvironmentVariable("TestVariableName", "My Value", "<option>")

However neither of them seem to add to this section. I have tried restarting the computer as well to see if it would take effect then. I have looked at technet along with countless other websites, but nothing I have tried has worked.

How can I set a system variable with PowerShell?

Answer 1

Run PowerShell as an administrator (to get the necessary registry access permissions) then call out to the .Net framework to set it:

[Environment]::SetEnvironmentVariable("MyTestVariable", "MyTestValue", "Machine")

NB. it won't take effect within the same process, you'll have to make a new PowerShell process to see it.