Method 1. Reboot
The following two methods do not restart
Method 2. Open cmd, enter the command set PATH=c, this command is to make the variables you write in path take effect immediately, then restart cmd for verification, add (echo %PATH% to view system environment variables)
Method 3. Note that even if the system environment variable takes effect, if the application you opened before is not closed and restarted (if you have not restarted the computer), then your application may not be able to read the system variable (haha, That's it), so you just close and restart the app