How do I programmatically restart a COM+ application running on a remote server from code in .NET?
You have to use the ComAdmin API through COM interop.
Put a reference on Windows\System32\Com\ComAdmin.dll, then:
COMAdmin.COMAdminCatalog catalog = new COMAdmin.COMAdminCatalogClass();
catalog.Connect(servername);
catalog.ShutdownApplication(AppNameOrAppID);
You can find the ComAdmin reference in MSDN here.
It's a COM API, and kind of wierd. Eg. you cannot instantiate a COMAdminCatalog, because it's an interface, not a class, so you have to use COMAdminCatalogClass to create a new instance. Use Visual Studio's Object Browser to look around in the COMAdmin namespace to find out these kinds of pitfalls.
EDIT (some note):
Actually, you CAN write
COMAdmin.COMAdminCatalog catalog = new COMAdmin.COMAdminCatalog();
and it works which is surprising because COMAdminCatalog is an interface. But it must be a trick of VStudio or the C# compiler, because the resulting assembly contains the following IL:
newobj instance void [Interop.COMAdmin]COMAdmin.COMAdminCatalogClass::.ctor()
So it somehow found out that the COMAdminCatalogClass must be instantiated, which is strange enough and a bit confusing too. If someone knows how it happens please comment.