Answer - In an NTFS file system inside the transactions all the data structure updates are performed. Prior to the alteration of a data structure a transaction creates log record containing information on redo and undo functions. Once a transaction is completed commit record information is stored in the logs. An NTFS system recovers from a crash by accessing information from the created log records. The first step is to redo operations of committed transactions and undoing those transactions which could not be successfully committed. Although the NTFS file system after recovering from a crash might not reflect the same user data prior to a crash but it can guarantee the file data structures are undamaged. It restores the structure to a pre-crash and consistent state.