An educational support software which instructs computer operation was developed to be utilized in lectures for hearing impaired students from a need of a teaching staff. We named the support software "SynchroniZed Key points Indicating Tool (SZKIT)." The SZKIT displays instruction texts, states of mouse button and modifier keys besides a mouse pointer. It is assumed that the SZKIT is intended to teach graphic designing software. In this research, it had a class to hearing impaired students using developed SZKIT. In this study, we evaluated comprehension through the lesson with Support Software "SZKIT" which Instructs Computer Operation to Hearing Impaired Students.