What does Windows error code 212 (ERROR_LOCKED) mean? Status / error code: Category: Constant name: Source: Operating System: Description: The segment is locked and cannot be reallocated. Could be also: ConstantTypeOS SYSTEM_SCAN_AT_RAISED_IRQL_CAUGHT_IMPROPER_DRIVER_UNLOADBugCheck CodeWindows Looking for a different code? Search another status or error code.