Abstract: A computer readable storage medium has instructions that, when executed by a host computer cause the host computer to perform a method of write protecting the storage medium and therefore preventing a non-registered user from changing the permissions log file. The instructions include: writing copies of control files of the host computer into the protected memory, writing a copy of a user permissions log file of the host computer into the protected memory, and changing a startup execute path function of the host computer to initially read the copy of the user permissions log file in the protected memory; and opening a write controlling circuit path to prevent access to changing the permissions log file.

Abstract: A removable drive is plug compatible with a host computer preferably through its USB port. The drive auto-launches upon insertion and runs read, write and execute functions on a resident file in the removable drive, tagging the control programs of the host computer that are responsible for these functions. The control programs are then copied to the removable drive and the path for these functions is changed to the removable drive. When the removable drive is right protected, the host computer is no longer a viable target for unauthorized access.

Abstract: An OS module is plug compatible with a host computer preferably through its USB port. The module includes a data signal gate, a hardwire write control device, a first memory device, and a second memory device. The first memory device holds portions of an OS that are unchanged during startup and operation of the host computer, while the second memory device holds portions of the OS that may be changed during startup and operation of the host computer. These components are interconnected for data signal flow between the host computer and the second memory device through the data signal gate, while data signal flow from the computer for writing to the first memory device is functional only through the data signal gate and the write control device. The first memory device may be read without limitation.