1. A computer that has enhanced resistance or immunity to viral, Trojan-horse, hacker, or other malicious code infection, the computer comprising: a processor; a memory coupled to the processor; a plurality of identified storage; and a switch selectively enabling access with only one of the plurality of storage with said processor and said memory by opening or closing a predetermined electrical circuit of a device to be switched; the selectively enabling access to the one storage disabling access among or between the processor, memory and another of the plurality of identified storage, wherein only a single storage is accessed at a time, preventing a virus, a hacking executable code, an infection, or other harmful or malicious element from executing or from contaminating another storage; a data port and means for mediating access of the computer over an external communications link with an external system; and the computer being operable in a connected state and in a disconnected state; the disconnected state being a state in which (i) the computer is prevented from communicating over the data port, and (ii) the data-store switch may enable access with any plurality of storage including permitting access with the first storage and the second storage; the connected state being a state in which (iii) the computer is permitted to communicate over the data port, and (iv) the data-store switch may not enable access with the first storage but may enable access with the second storage; and the permitting or preventing access to particular storage depending on whether the computer is communicating or not communicating with an external system via the data port and operable for isolating data received only to the second storage so that if the data received has a virus, a hacking executable code, an infection, or other harmful or malicious element it is confined to the second storage.