Windows Registry actually a system file that can store all information about the system and the application files which install in to the computer system. It can store information such as where the application programs and their icons are stored, all information about DLL files, all information about the drivers, and store the list of all start-menu shortcuts. Everything user does in windows is recorded in the registry file. The all recent activities of the user are saved in it such as path of open documents (images, songs and videos), list of recently installed and uninstalled programs. All information stores in registry in the form of keys. 

Registry file stores more than thousands of entries, and when user does any task then new entry are created. When the registry file becomes huge then it also slowdown all activity of the computer system, sometimes it display registry related errors, it also display some error when user want to install and uninstall any application programs, pc takes more time to start up, Restarts PC when any application program is executed. 

So to increase the performance of the computer you need to clear the unwanted registry keys from your computer system. But if any error occurred while cleaning the registry keys then it affect your windows operating system that may require reinstalling of operating system.

You can clean your system registry keys manually, but at your own risk because one wrong step can corrupt your computer system. 

Cleaning your windows Registry keys manually:

NOTE: Create a backup of your Registry file and then do any removing task on the registry file.  

Click on start menu- select Run- Type regedit and press enter.

Registry file will be open delete the unwanted keys from the registry file carefully. 

Cleaning your windows Registry keys using Registry Repair Software:

To repair your windows Registry file and to increase your system performance you can use Registry Repair tool. This tool is very efficient and removes all unwanted registry keys from the windows. It will also repair the key value of the windows registry file. This tool can repair the all registry error of your computer system and make your PC error free.