It is made possible to update software appropriately. When additional
software is installed, update management data for the additional software
is generated. When the update management data for the additional software
is attached to the additional software in advance, that data is used. If
the update management data is not attached, cycles for confirming the
presence of updates and the like are determined based on the nature of
the software, and the update management data is thus generated. Then, the
generated update management data is set in an update management table.
The presence of software updates is checked for based on the cycles for
confirming the presence of updates in the update management table.