A computer-simulated software training system (CSSTS) delivers a specific form of computer-based training in which participants are allowed to select various training features within a simulated software environment. Given the growing use of these systems as end-user training (EUT) aids, there is a need for greater understanding of how participants use these systems, as well as whether participant-controlled learning environments are truly effective. The present research examines how a particular learner characteristic, software self-efficacy, drives appropriation in a high learner control, CSSTS environment. Contrary to notions in the literature, results from spreadsheet and database software training courses reveal that pre-training specific software self-efficacy constitutes a significant, negative predictor of faithful appropriations of the CSSTS. This research also establishes a positive relationship between faithful appropriation and increases in software self-efficacy (SSE). In essence, faithful appropriations lead to greater increases in SSE, which influences software skills performance. In addition, the research validates prior EUT research by extending prior findings to a database training environment. A psychometrically sound measure is put forth to capture database self-efficacy.