More Than One Instance of Program Detected


Only one person is able to open the Win32 console on a system at any given time. An error is displayed if a second person tries to open the management console while someone else has it open. The error states, More than one instance of this program detected. Why does this occur?


This behavior is by design. Specifically, as we do not provide our own networking (we use Windows networking), the host system will use whatever connection is available to connect to a machine. This means that we use the authentication already established by that connection. Consequently, two people who would otherwise not normally be able to administer each other's systems would potentially be able to do so if we did allow the tool to be launched at the same time.

For example, if Sheldon launches the tools and uses RPM to administer his systems, Windows will maintain a connection to those machines for a period of time, and to which he has authenticated as Sheldon. If Leonard, at the same time, opens RPM Package Manager in his session and attempts to connect to those same systems, he will succeed. He will also authenticate using his own credentials.

To avoid these issues with security, we artificially limit concurrent access to the Win32 application to one user at a time per system.