As software plays increasingly important roles in modern society, reliable software becomes desirable for all stakeholders. One of the root causes of software failure is the failure of the computer hardware platform on which the software resides. Traditionally, fault injection has been utilized to study the impact of these hardware failures. One issue raised with respect to the use of fault injection is the lack of prior knowledge on the faults injected, and the fact that, as a consequence, the failures observed may not represent actual operational failures. This paper proposes a simulation-based approach to explore the distribution of hardware failures caused by three primary failure mechanisms intrinsic to semiconductor devices. A dynamic failure probability for each hardware unit is calculated. This method is applied to an example Z80 system and two software segments. The results lead to the conclusion that the hardware failure profile is location related, time dependent, and software-specific.