Abstract: There is disclosed a method and apparatus for controlling access to and corruption of information in a computer system. In known “PC Virus” protection methods the boot partition becomes “Read Only” when the system is in Supervised Mode. However, Microsoft Windows, although not strictly self-modifying, does require that certain files located within the Windows directory, can be written to.

Abstract: There is disclosed a method and apparatus for controlling access to and corruption of information in a computer system. In known “PC Virus” protection methods the boot partition becomes “Read Only” when the system is in Supervised Mode. However, Microsoft Windows, although not strictly self-modifying, does require that certain files located within the Windows directory, can be written to.

Abstract: There is disclosed a method and apparatus for controlling access to and corruption of information in a computer system. In known “PC Virus” protection methods the boot partition becomes “Read Only” when the system is in Supervised Mode. However, Microsoft Windows, although not strictly self-modifying, does require that certain files located within the Windows directory, can be written to.

Abstract: A method and apparatus for controlling access to and corruption of information in a computer system. In known "PC Virus" protection methods the boot partition becomes "Read Only" when the system is in Supervised Mode. However, Microsoft Windows, although not strictly self-modifying, does require that certain files located within the Windows directory, can be written to.

Abstract: An apparatus and method restrict the corruption or destruction of data held on a storage medium forming part of a computer system by hostile programs such as "viruses"by employing a "Supervisor" which controls the reading, writing and formatting of sectors within partitions of a storage medium. The control is dependent upon which type of partition the sector is within, i.e. the boot partition, or an active or inactive general partition, and which type of data the sector contains, i.e. operating system or user information. The Supervisor may be implemented in hardware or firmware, and preferably provides a processor which is inaccessible to the user and to any virus contained in any partition of, for example, a hard disk. The computer system may be reset should an attempt be made to perform a prohibited read, write or format operation.