Mechanism for closing back door access mechanisms in personal computer systems

Methods, devices, and systems for closing back door access mechanisms. A processor includes a first register configured to store one or more hardware-debug-test (HDT) enable bits, a first control logic coupled to receive a plurality of HDT input signals, and a second control logic coupled to the first register. The first control logic is coupled to access the first register. The second control logic is configured to store one or more default values in the first register in response to a reset of the processor. Another processor includes a first control logic coupled to receive a plurality of microcode inputs, a first register coupled to the first control logic, and a second control logic coupled to the first register. The first register is configured to store one or more microcode loader enable bits. The second control logic is configured to store one or more default values in the first register in response to a reset of the processor.