Powershell: Reload the path in PowerShell

If I have an instance of PowerShell ISE running and I install something that modifies the PATH or I modify it in any way outside of PowerShell then I need to restart PowerShell for it to see the updated PATH variable.

Is there a way to reload the path from within PowerShell without restarting it?

Just to bring Rob's comment to light:

$env:Path = [System.Environment]::GetEnvironmentVariable("Path","Machine") + ";" + [System.Environment]::GetEnvironmentVariable("Path","User") 

Try getting the machine path and assigning it to the session's path.

$env:Path = [System.Environment]::GetEnvironmentVariable("Path","Machine")

Easiest way, use Chocolatey (freeware). It works for both CMD and PowerShell. Then you will be able to reload PATH (with variable expansion) with a simple command:

refreshenv

Installation from cmd (requires administrator rights):

@"%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -InputFormat None -ExecutionPolicy Bypass -Command "iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'))" && SET "PATH=%PATH%;%ALLUSERSPROFILE%\chocolatey\bin"

Example usage:

> SET JAVA_HOME=c:/java/jdk6
> SET PATH=%JAVA_HOME%/bin
> ECHO %PATH%
c:/java/jdk6/bin

> SET JAVA_HOME=c:/java/jdk8
> refreshenv
Refreshing environment variables from registry for cmd.exe. Please wait...Finished..
> echo %PATH%
c:/java/jdk8/bin