1. A computer-implemented method for performing self-healing at a computer host, comprising: providing, at the computer host, at least one file of instructions which defines a plurality of self-healing tasks; providing, at the computer host, a self healing engine for executing the self-healing tasks using the at least one file of instructions, the at least one file of instructions being updateable independently of the self-healing engine; receiving an update definition via a remote download at the computer host; and updating the at least one file of instructions with the update definition by inserting the update definition into the at least one file of instructions, to thereby achieve an updated self-healing functionality.