A method of recovering from a system failure. Also called a "snapshot image," a checkpoint is a copy of the computer's memory that is periodically saved on disk along with the current register settings (last instruction executed, etc.) and any other status indicators. In the event of a failure, the last checkpoint serves as a recovery point. When the system has been fixed, the restart program loads the last checkpoint and starts the computer with the next instruction in line. However, any transactions in memory after the last checkpoint was taken and prior to the failure will be lost.