Method and Apparatus for Securely Backing Up and Restoring a Computer System

Data of a computer system can be secured from malware. During a Primary Operating System (PrimaryOS) run-time, the system determines if the computer system has been compromised and, if so, a Trusted Operating System (TrustedOS) is launched and assumes control of the hardware resources and the software resources of the computer system. The TrustedOS obtains a cryptographic key that is inaccessible to the PrimaryOS. The TrustedOS uses the cryptographic key to disable writing to a first portion of the storage media that includes the first set of logical block addresses. The PrimaryOS can incrementally back-up files to a second set of logical block addresses on a second portion of the storage media. Control of the hardware resources and the software resources is returned to the PrimaryOS.