Since GN4 version 2.0 you can define what to do when an user launch Fred, Ted or Shell more than once on the same PC.
1.Import .../Config/Data/GN4/securityScope_Default.xml. This adds a new parameter to the Security scope Default. Do not change anything here.
2.Edit a group or user and in Parameters, add the ClientAppMulti numeric parameter.
3.Set its values to 0 = Always open multiple instances (default), 1 = deny multiple instances (maximize current application), 2 = prompt what to do.
Note
The flag is cached into %appdata%\TeraDP\GN4\MultiInstance.dat file when closing the GN4 applications, so on the next startup, check is done before logging and configuration load.