Disaggregated secure execution environment

A computer adapted for use in limited function operating modes comprising:na secure hardware interface providing an interface between a secure execution environment and a plurality of functional circuits of the computer;the plurality of functional circuits including at least two or more of a processor, a graphics processor, an I/O interface, a BIOS memory, a non-volatile storage memory, and an external bus interface, each of the plurality of functional circuits connected via a bus external to the plurality of functional circuits;a secure execution environment having secure storage and controlling disaggregated enforcement functions in each of the respective functional circuits, the secure execution environment including at least a metering function that monitors usage of the computer according to a policy at least partly secured in the secure execution environment;the metering function measuring CPU usage charged to a stored value balance in the secure storage; andat least a first of the enforcement functions in a first of the functional circuits, when activated by the enforcement function, in turn activates a limited function mode in the first functional circuit when the metering function determines usage is not in compliance with the policy, the limited function mode removing or reducing some but not all functionality of the first functional circuit such that at least some functionality of the first functional circuit continues to be available for use by the computer.