Prior computer experience with information technology has been identified as a key variable (Lee, Kozar, & Larsen, 2003) that can influence an individual's future use of newer computer technology. The lack of a theory driven approach to measuring prior experience has however led to conceptually different factors being used interchangeably in published research. As a result cumulative knowledge building from research on the understanding of the influence process of prior computer experience is impeded. This study analyses the prior research on prior experience and develops two conceptualizations of prior experience: habit and computer proficiency. Habit reflects the automatic response in the presence of a cue (e.g. a new technology) that is formed over a period of time, while computer proficiency represents the knowledge/expertise component. Based on the Employee Self Service (ESS) Model, the effects of these two proposed conceptualizations are examined empirically. The ESS model considers the usefulness and ease of use of the technology along with normative influence to be key determinants of technology acceptance. Habit and Proficiency are hypothesized to have direct effects on the usefulness and ease of use of the technology. Habit is hypothesized to also have direct effects on intentions to use a technology. Regression analysis of survey data collected from 737 students in a major university located in the Northeast who are faced with using a new class enrollment software system indicates that proficiency has direct effects on perceptions of information technology's usefulness and ease of use, with habit having curvilinear effects on adoption intentions in addition to linear effects on the two key determinants of intentions to use a technology i.e. usefulness and ease of use of the technology. The results indicate that beyond a certain level of usage, individuals may automatically reject a newer technology that required more computer use/time. Implications for future research and for practitioners are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]