PURPOSE: To provide the fault-time processing restartng system of a computer system which automatically obtains fault information at the time of a fault in a system and automatically resumes a processing with an optimum information processing program.

CONSTITUTION: IPL previously registers a main program and a fault information collection program (SISP) into a main memory (S11). When the fault is judged to occur (S12), SISP is called (S14), a re-IPL control program (SIPLP) is registered (S15) and SISP stores fault information on the main memory and a working memory into a magnetic disk device for fault information storage (S16). Then, SIPLP loads the optimum main program from a magnetic disk device for IPL and it is registered in the main memory. CPU restarts the processing (S18).