Pervasive environments are characterized by a large number of embedded devices offering their services to the user. Which of the available services are of most interest to the user considerably depends on the user's current context. Spontaneous service discovery and selection is one of the most important fields of research in pervasive computing. In this paper the authors will present an enhancement of ubiquitous computing discovery mechanisms adding context handling capabilities to Web Services for Devices in Pervasive Computing using UPnP as an infrastructure to address these implicit requests. User preferences, network and location are described by a formal context model ontology that is based on two levels: a generic level and a domain specific level. As compared with previous research, the authors' method uses location aware, UPnP infrastructure, web service for devices and the notion of proactivity in pervasive computing to continuously present the Spontaneous most relevant services to the user or device in response to changes of context, services or user preferences.