In this paper, we propose a social semiotic approach to studying PowerPoint in university classrooms. Our approach is centred on two premises: (1) PowerPoint is a semiotic technology that can be integrated into the pedagogical discourse of classrooms, and (2) PowerPoint technology encompasses three interrelated dimensions of social semiotic practices: the design of the software, the composition of the slides, and the slideshow-supported presentations, i.e. lectures. Using this approach, we explore how PowerPoint has been used in seven cultural studies lectures in an Australian university. Our analysis demonstrates how multimodal resources in PowerPoint have been used for pedagogic recontextualisation. More specifically, it shows how different semiotic resources have been deployed and combined to recontextualise two key types of knowledge--signifying practice and subjectivity--in the classroom discursive space, and how different strengths of pedagogic framing are achieved multimodally.