I dont know of an option in Plex to prevent saving the user id besides doing it yourself.There are a number of options to try: 1) Make the .ini read only (dont know if it will cause problems, but also prevents keeping different user panel settings)2) In your top level function or MDI, always clear the user id in the .ini file in case it was saved3) Write your own logon box (you already have that, but could be problematic on a shared .ini) This however indicates that you running your applications from a common shared folder. This is bad as it will degrade application performance as all DLL's are loaded across the network. If you running in a thin client environment, the best is to copy the .ini file to each users, profile folders.