The invention relates to a
system for separating the operation
system and a relative method, wherein it comprises: a mother operation
system module, at least one sub operation system module for containing the modify information of user on the mother operation system module, a system separating module and an external memory
access control module for recording the disc spaces of mother / sub operation system module; said system separating module via the user command instructs and / or build sub operation system module, to instruct and / or modify the
disc space and disc blank space of mother / sub operation system module, and detect the read / write access of mother / sub operation system modules on the disc. The invention can build different operation systems without occupying more space of disc, to separate the operation system and reduce the system abundance, increase the safety and reliability, to protect the
user information at different sub operation system modules.