Updating environment strings
If you are on a personal connection, like at home, you can run an anti-virus scan on your device to make sure it is not infected with malware.
If you are at an office or shared network, you can ask the network administrator to run a scan across the network looking for misconfigured or infected devices.
Say you have a production server which hosts a variety of apps and a new app needs a particular Environment variable to run. After the changes are saved, Explorer broadcasts a message to all windows to inform them of the change.
You do not want to reboot it while users are connected to your other apps. I don't like the wait-until-a-good-time-to-reboot option. Any programs spawned via Explorer after this should get the updated environment, although already-running programs will not, unless they handle the setting change message.
As a best practice, you should save all sensitive values in an environment and provide a dummy environment for the user to fill in.