In distance education, students and teachers are at different places and interact with each other with the help of different technologies. Broadcast television, two-way video conferencing, asynchronous learning mode, virtual learning environment (VLE) and content based multimedia computer based trainings (CB-MCBTs) are some of the technologies used to provide distance education. Content Based Multimedia Computer Based Trainings (CB-MCBT) is a computerized learning environment. The acceptance of computerized learning environment is based on its usability. And usability in any computerized learning environment is supportive to learners and it increases their learning experiences of learners. Authors of this research have evaluated usability of CBMCBTs, specifically CB-MCBTs designed by AIOU. Usability evaluation has been performed to find out usability issues in CB-MCBTs, and figured out requirements of learners regarding CB-MCBTs. To figure out usability issues in CBMCBTs authors have used inquiry technique with focus group and questionnaire. Authors have proposed usability criteria to evaluate usability of CB-MCBTs. Each element of proposed criteria is based on principle of user interface design, and three main usability aspects: effectiveness, efficiency, and satisfaction. Development of CB-MCBTs in AIOU is nice and unique effort in the field of computer based trainings. However if these CB-MCBTs are designed to support distance education, then AIOU should focus on the availability of CB-MCBTs to the students, feedbacks within CB-MCBT and feedback from university to students and completeness of these CB-MCBTs regarding features and facilities required by the students. This research also gives recommendation to AIOU for improvements in CB-MCBTs. These recommendations are helpful to fix usability issues in CB-MCBTs and to make these CB-MCBTs according to the requirements of learners.