African Americans and Hispanic Americans historically have been underrepresented in U.S. jobs in the fields of STEM in large part because of the usability of technology. In this research, the goal was to discover the usability factors relative to operating systems that may limit African Americans and Hispanic Americans from pursuit of computer science higher education. For the purpose of this study, "usability" refers to the "appropriateness of purpose." Categorized by three factors, appropriateness of purpose can be defined as (i) the effectiveness of the users' ability to complete tasks while using technology and the quality or output of those tasks, (ii) the efficiency and the level of resources used in performing tasks, and (iii) the satisfaction or users' reaction to the use of technology (Brooke, 2014). This research examined quantitative analysis based on students' routine computer task knowledge using a survey questionnaire and the SUS. The population included high school students responding to questions on common tasks and usability. A web survey was conducted to assess the measurement and understanding pattern demonstrated by the participants. The quantitative analysis of the computer usability included ANOVA, independent t-tests and orthogonal contrasts. The analysis of the SUS measured usability and learnability. The results of the data analysis showed that the combined African American and Hispanic group has a mean computer usability score that is significantly lower when compared with the other ethnicities and the SUS findings included the highest gap among this most underrepresented group in the STEM field.