The worst thing that Microsoft could create in Windows was the Windows registry. Its so delicate that if you do something wrong with the registry, everything is gone. This means that registry needs to be backed up regularly so that if there is a system crash due to corrupt registry or invalid system state, we can easily revert the system back to the previous state when we last saved the registry. Here is a tool that can do the job of backing up your Windows registry and it takes the responsibility of remembering everything. Its name is ERUNT (Emergency Recovery Utility NT). Features Backup the Windows NT/2000/2003/XP registry to a folder of your choice System and current user registries selectable. Command line switches for automated registry backup and restoration. Restore the registry in Windows 9x/Me/NT/2000/2003/XP and MS-DOS. Included NTREGOPT program for optimizing the registry. Download ERUNT from here It is a small package around 772KB. When downloaded, double click the setup file to install it. The default installation folder is Program Files\ERUNT. It creates two shortcuts on the desktop. One is ERUNT (main application executable to backup the registry) and the other is NTREGOPT (used to optimize the registry). Backup Registry Manually To backup the Windows registry, just run ERUNT and press OK when prompted. Then it will ask you where to save the registry. By default, it will save in Windows folder. The advantage of saving the registry backups in Windows folder is that you can access it easily using recovery console. You can configure which registry hives you want to backup, system registry, current user and other open user registries. By default, ERUNT creates a new folder for each registry backup using the current date as folder name. This is advantageous in the sense that you can create as many backups as you want without worrying about the naming scheme. It also asks if the folder does not exist and clicking yes automatically creates the folder. Then the progress bar will appear showing the progress of registry backup process. Please note that the system may hang during the registry backup. Dont do anything, it will be OK after a few minutes. Automatic Backup Once installed, ERUNT also creates a backup of registry after every system startup. By default, these backups are saved in %SystemRoot%\ERDNT\AutoBackup\ So if anything goes wrong, just go to recover console, restore your system state from the latest backup. Restoring Backups Restoring the backups using ERUNT is very easy. Just go to the folder where you have taken the backup. For example, for the last automatic backup, go to C:\Windows\ERDNT\AutoBackup\ and select the date folder you want your system to be restored. Open the folder and double click ERDNT.exe. This will launch the restoration wizard. Press OK. Now you will see the restoration options. Select the options you want and then click restore. Thats all you have to do. Your system will be restored to the previous working system state.