Knowing students' belief of their capability in using the computer tasks is a key competency, necessary for learning in technology-enhanced environment. To generate a valid and reliable instrument for measuring computer self-efficacy (CSE), this study aimed to explore the underlying factors of CSE, and to find out the relationship with students' academic achievement. The respondents' CSE was assessed in terms of two dimensions, namely, general and advanced computer self-efficacy. The results revealed a statistically significant difference between Arts and Science students in terms of their CSE in favor of Science students, and also proved that there was no statistically significant correlation between students' academic achievement and their computer self-efficacy. The results provide the foundation for the instrument that allows researchers to determine students' general and advanced computer self-efficacy, and information that can be useful in enhancing students' academic achievement.