The study was conducted with 605 high-school students in 13 classes of a typical high school in northern Taiwan. In the paper, we will detail the past conduct of the course, the revised PBL-induced course design, and our experimental design. We will discuss how we circumvented the usual challenges faced with PBL and some of the pragmatic issues faced during our implementation. Our experimental results showed that PBL did enhance students' learning in computer science concepts and their software usage skills. Furthermore, the classroom atmosphere was changed from the teacher-directed atmosphere into lively students-centered atmosphere in which students became active learners in and out of the classroom. We have also concluded that the blending of cooperative learning with PBL in a computer class is feasible.