The increasing use of technology to enhance learning means both disabled students and higher education institutions face the challenge of adapting technology to meet the educational and special needs of students. As most e-learning systems are not designed to meet special needs, it is imperative to look for newer ways of designing e-learning systems to ensure that they are disability-aware and meet their assistive technology needs. In this light, this paper summarizes the result of research to seek better ways of enhancing learning for disabled students. Here, the resultant ONTODAPS system is introduced, including the methodology developed to design the system, its architecture and evaluation by 30 disabled students. The results of the usability evaluation are presented and discussed. It is hoped that researchers, instructional designers and developers of e-learning systems would look to this paper to gain insight into the design and development of disability-aware e-learning systems that will ensure that they are both accessible and usable to disabled students.