A method and system for instantiating COM components in custom contexts are proposed. The solution of the invention is based on an auxiliary component, acting as a factory (215). Whenever a client (205) needs to instantiate a new target component in a desired custom context, it calls a dedicated method exposed by the factory, passing the identifier of the target component together with information about the custom context. The factory starts execution of an additional module, operating as an impersonator (225), in a new process (230) conforming to the custom context. The impersonator then instantiates the target component in its own process. The impersonator passes a pointer for the target component to the factory (calling a further method that is exposed by the factory); the factory in turn returns that pointer to the client.