Abstract: A boot failure recovery system operates to diagnose a failed system boot in a computer operating system which boots by bootstrapping from a boot sector (12) of a storage medium (10) using configuration information (82). The boot failure recovery system includes an agent (24) which monitors operating system files used during system boot and which stores information regarding changes to the system files to a change file. A repair module (22) analyzes the change file to determine the cause of the failed system boot. A boot check module (16) responds to initiation of a system boot by determining if a prior system boot was successful. Boot check module (16) causes execution of a first boot sector code module (16) upon occurrence of a successful prior system boot and causes execution of the repair module (22) upon occurrence of a failed prior system boot.