I hope you are already aware of what is Windows Registry. Basically it's a database that contains many configuration information of windows software and about all hardware. Whenever you install any software, Windows store information about it in registry in a Key Value pair Format.
If you are using windows XP, then you can check the windows registry by following the below process:
Run(command mode) -> regedit -> Enter
You will get the below screen:
As you can see registry contains data in hierarchical format. You can check any installed software for more information.
Why We need Windows Registry Cleaner?
Whenever you install any software or new hardware, windows store it's configuration value in registry. Again whenever you uninstall the particular software or hardware, sometime windows doesn't delete this configuration information from registry and this may slow down your system.
For better performance of your PC, those information from Registry should be deleted. You can either do it manually or using the best registry cleaner software. But if you are going to do it manually, remember to keep a backup of current registry. Because by mistake if you change something that you should not have, your system windows may get corrupted.
