?Windows Registry is the database which defines all the settings and options available for Microsoft Windows. This database holds information how various hardware, software (operating system and non-operating system) and PC preferences have been set. So, each time you make some changes to File Associations, software, Control Panel Settings and System Policies, Windows Registry gets correspondingly altered. At times, your system might prompt that it has encountered a registry error and hence it cannot continue booting. Such errors indicate that Windows Registry is unable to carry out Input/Output operations while dealing with one or more of its files. You might need to reformat your hard disk Recovery in such cases, thereby restore the deleted data from the most recent data backup. However, the inconsistencies in data backup lead you to use data recovery applications- Tools to safely recover the lost data. As an example, when you try to boot a Windows-based system or perform a registry operation, the screen might display the following error: "STOP 0x00000051 (parameter 1, parameter 2, parameter 3, parameter 4) Or "REGISTRY_ERROR" Here, parameter 1 and parameter 2 are reserved parameters, parameter 3 denotes the pointer to the hive and parameter 4 denotes the return code of HvCheckHive. Cause Registry errors are generally encountered when registry observed I/O errors while making an attempt to read one of its files. It can occur due to following possible reasons: ? Hardware issues ? Failure of refresh condition (used by Windows security system) ? Limited resource ? File system corruption Solution To troubleshoot registry errors in Windows, you should try following these steps: ? Run hardware diagnostics and determine the hardware in question. You should replace the damaged hardware or perform the diagnostic steps ? Try restarting the system. This will resolve the refresh condition failure and limited resource like problems ? Run chkdsk to correct file system errors. If file system corruption persists, reformat the hard disk and restore from backup. There might be situations when you find that data backup as invalid or absent. To cope up with such scenarios, use data recovery software. Such tools serve as advanced data recovery software utilities with rich interface and safe recovery techniques. Stellar Phoenix Windows Data Recovery is a comprehensive recovery tools for Windows 7 RC 1, Vista, XP, 2003 and 2000 based systems. It is a non-destructive tool with advanced features like Drive Cloning, Disk Imaging, Drive Status etc. This advanced data recovery software supports FAT32, VFAT, NTFS and NTFS5 file systems.