In 2015, a Member of the Executive Council (MEC) of the Gauteng provincial legislature, South Africa, introduced the "Classroom of the Future" programme in previously disadvantaged schools, allowing an integration of information and communication technology into classrooms. In this article we focus on the sustainability of ICT in these schools. We regard sustainability as meeting one's needs without compromising the ability of future generations to meet their own needs. The sample constituted 18 participants from 6 disadvantaged schools in the Classroom of the Future initiative. Semi-structured face-to-face and telephonic interviews were employed for data collection. Our results show that ineffective teacher professional development for ICT, and inconsistent and timeous service delivery from the Gauteng Department of Education (GDE) technicians/teacher trainers were a major deterrent to effective ICT implementation. Additionally, the phasing-in approach to the rollout of ICT was a serious challenge to ICT sustainability in schools. We recommend improved teacher professional development initiatives pertaining to ICT to be instituted in schools where heads of department take responsibility for empowering post-level one (PL 1) teachers on ICT to improve classroom learning. We also advocate for new improved service delivery from GDE technicians/teacher trainers, who are held accountable for fulfilling their mandates.