I posted the article below in the PowerPro forum ... no replies yet. But I have to wonder if TCC has any part in this (I doubt it) and whether the few PowerPro users in this audience might have any idea what's going on. Below is my post to the PowerPro forum. I have a PowerPro button: Command: d:\tcmd9\tcc.exe Start: Hidden Parameters: /c start %@regquery["HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\9.0\ProjectMRUList\File1"] TCC.EXE is the second-latest version of what was the 4NT command interpreter. My PowerPro button effectively starts Microsoft's DevEnv with my last project active. But if there's already an instance of d:\tcmd9\tcc.exe running, and I click the PowerPro button, the running instance becomes hidden (and the desired task gets gone, so I suspect PowerPro is also starting a new, hidden, instance). Even stranger, if an instance of d:\tcmd10\tcc.exe, a newer version, is running, the same thing happens. I don't think TCC.EXE does any DDE (i.e., you can't give a command to an already running instance). So what's happening? Is PowerPro doing exactly what I said (starting a new instance) and, in the process, hiding every instance of any TCC.EXE it can find? In any event, how can I stop that?