Applies To:
  • CitectSCADA 4.X

As a security measure, I would like to stop users from switching back to Program Manager or Explorer in Windows NT. 

To prevent users from switching from Citect back to Program manager or Explorer in Windows NT you can run Citect as the SHELL. Normally Windows NT runs either Program manager or Explorer as the shell (depending on your version of NT). You can change this so that another program is run as the shell when NT starts, to do this you must use the Regedt32.exe to edit the following registry value. HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\CurrentVersion\WinLogon\Shell. The default for this in NT V3.51 is PROGMAN.EXE and in NT 4.XX it is EXPLORER.EXE. To run Citect as the shell, change the setting to C:\CITECT\BIN\CITECT32.EXE.

WARNING: Make sure you can get back to REGEDT32.EXE to reverse this procedure if required. To do this you should have a command in Citect as follows: Command: Exec("C:\WINNT\SYSTEM32\REGEDT32.EXE"), test this command before modifying the registry. You should also have a command to run the program manager or explorer if required, eg Command: Exec("EXPLORER.EXE") (for NT V4.XX). These commands should be assigned a high privilege level so that the average user cannot execute them.

NOTE: You may need to delay the startup of Citect when using serial ports to allow other drivers to load.  See article Q2394.