[roman]

Empezado por gluglu

Lo que sí he podido chequear, es que ExecInfo.hProcess es siempre 0 en el caso de que ejecute el código indicado. Realmente no sé por qué es así.

¡Uf! La tienes complicada. Esto dice la documentación:

hProcess

A handle to the newly started application. This member is set on return and is always NULL unless fMask is set to SEE_MASK_NOCLOSEPROCESS. Even if fMask is set to SEE_MASK_NOCLOSEPROCESS, hProcess will be NULL if no process was launched. For example, if a document to be launched is a URL and an instance of Internet Explorer is already running, it will display the document. No new process is launched, and hProcess will be NULL.

// Saludos