deferred procedure call. A queued call to a kernel-mode function that will usually be executed at a later time. DPCs are used by drivers to schedule I/O operations that do not have to take place in an ISR at a high IRQL, and can instead be safely postponed until the processor IRQL has been lowered. For more information, see the topic, DPC Objects and DPCs. DPCs can also be used with timers. For more information, see the topic, Timer Objects and DPCs.