One trick pony to force environment refresh under Windows.
When you modify environment variables under Windows, you normally need to logout or restart the computer for those changes to take effect.
To avoid that, Windows offers a mechanism that notifies all running process of environment changes to act accordingly.
The procedure is described in Microsoft support article KB104011.
Certain tools like WiX do not broadcast this notification when changing environment variables.
If you create a installer with WiX, you will need to use something like PowerShell scripts, which might not be installed or allowed under some systems.
Instead, this provides a simple, small application that does just that: broadcast the environment changes to all open applications.
I blatantly stole this from MSDN and Microsoft support, so cannot put a copyright notice here.