This invention provides a program product for a virtual computer that partitions a physical computer into a plurality of logical partitions through a hypervisor and runs an OS on each of the logical partitions, the program product including: a procedure (S1) of detecting an exception or an interruption occurring in the physical computer; a procedure (S2) of identifying an OS on a logical partition where the detected exception or interruption occurring; a procedure (S4) of copying a given storage area that contains an instruction that is the subject of the exception or interruption from a storage area where the identified OS is stored to a storage area that is managed by the hypervisor; a procedure (S6) of replacing, in the copied storage area, the exception or interruption subject instruction with an instruction that substitutes for the exception or interruption subject instruction; and a procedure (S7) of moving a location where the physical computer executes an instruction to the copied storage area.