A computer, having: a first OS to which a first processor core group is allocated; and a virtualization module to which a second processor core group is allocated, wherein a virtualization module registers interrupt handler processing for resetting the second processor core group, wherein a first OS has: a monitoring module for monitoring the virtualization module; and an interrupt control module for obtaining identifiers of the second processor core group at a time of booting of the virtualization module, and, when the monitoring module determines to reboot the virtualization module, issuing resetting interrupt to the processor cores of the second processor core group that are associated with the kept identifiers, wherein the second processor core group receives the resetting interrupt and executes the interrupt handler processing to reset its own processor cores, wherein the interrupt control module issues startup interrupt to the second processor core group.