For those who do not know what it is, Wikipedia defines it as " a hierarchical database that stores configuration settings and options on Microsoft Windows operating systems. It contains settings for low-level operating system components as well as the applications running on the platform: the kernel, device drivers, services, SAM, user interface and third party applications all make use of the Registry. The registry also provides a means to access counters for profiling system performance."
Coming back onto the importance of registry, a small case of wrongful fiddling can cause it to become corrupt. That can often cause a program to crash when it's working or worse, not make it work at all. In some instances it can cause Windows to function improperly too. Thus it becomes imperative that the registry be maintained. A maintenance isn't too hectic. Just backup regularly and in case of corruption, can be restored back from the corruption.
For this very purpose, we have a nifty tool called ERUNT (Emergency Recovery Utility for NT). This is a light and easy to use tool for backing up and restoring the registry in Windows NT/2000/2003. The latest version works with Windows 7 and it can be used on Vista too keeping User Account Control turned off.
Backing up is very simple. The screenshots below are self explanatory.
Restoring back is pretty simple too. Check out the images.
Click OK and you are done!
Remember to back up regularly!
Download ERUNT from the official website