PURPOSE: To easily confirm an installation result when an installation medium with files recorded is installed on a magnetic disk.

CONSTITUTION: This installation confirmation system is provided with an installation information area 9 in which installation information inputted from the installation information medium is stored, a file retrieval information area 8 in which information on the result of retrieval of a file on the installation medium and the result of installation based upon the installation information is stored, and a comparing and file control means 10 which compares the contents of the installation information area 9 and file retrieval information area 8 with each other, and then updates the installation information according to the comparison result and controls writing-back operation to the installation information medium.