Users should be aware that all menu options are intended be executed sequentially, i.e. WinGX is NOT a multitasking program system. This is because many programs will wish to access or write to the same files, and this would result in chaos in a multitasking environment. As each program (i.e. menu option) is initiated, a message appears in main menu ACTIVE MODULE status bar, which indicates a program is running. Some programs do not produce output immediately, but this message will tell you that something is going on. As the program finishes, the message changes to "none". Only at this stage is it possible to start up another program.
Many programs in the WinGX system, e.g. PLATON, SHELXL97, SIR92 and most of the programs in the Graphics menu are launched as external processes. If these external processes are "locked" then WinGX will not return control to the user until the external process has finished execution (either normally or through a run-time error). It is usually necessary to close all Windows associated with this external process to ensure this happens. The user may select whether external processes are "locked" from the File-System-Preferences menu item. The default is that NO processes are run in locked mode. Note that this is different from previous versions of the program.