The goal of this investigation was to evaluate the impact of training and the effectiveness of different types of knowledge retention activities delivered by computer-based training (CBT) programs. This study focused on a computer-based learning system called the Profound Learning Delivery System (2005) (PLS). PLS is an application designed to improve knowledge retention in adult learners undertaking CBT. This study used a pretest-posttest experimental design to compare adult learners’ knowledge of Microsoft Outlook (Outlook, 1997) before and after a CBT session. Participants were trained using two different computer-based instructional programs: a commercially available software program matched for comparison purposes, and PLS. This comparison involved three different formats for post-instruction retention activities that were: no review activities; user generated review activities; and, program generated retention activities. Results indicate that despite random assignment, there was a significant difference between the groups 60 days after training. This result demonstrated that PLS has potential worth exploring.