Most of your system related issues are concerned with the Windows Registry; they should be repaired or fixed as soon as possible to keep your computer updated and efficient. All modern Windows OS have the registry database or registry system which stores all configuration settings about the associated components in the computer system. If a small configuration gets corrupted by any means it will affects directly the related software or hardware in return. So the integrity and protection of this registry is highly required all the time if you want your PC to perform consistently in a better way. The registry may be corrupted in many ways or many factors or many causes can corrupt the Windows registry.
If you install a program the registry adds the value and configuration setting in it for the installed one. If it is not installed completely the location and other information gets stored partially or in a corrupt form, it create many issues and Windows Registry problems later. If you uninstall a program from your computer some of the remnants remain in the windows registry. It has the capability as it is designed and it is intended to damage the registry before it does anything else. Another thing is viruses and other malware. It can cause a great damage to windows registry. A virus modifies the windows essential registry entries so that the security things cannot detect it and it can do whatever task it is supposed to.
These are the main facts that often corrupt the windows registry and subsequently they create more system issues. For removing a virus you need a good antivirus program which can eliminate all malicious entries from your system and registry, actually an antivirus is not designed to repair the corrupt windows registry. So a reliable registry cleaner is required.
For removing thousands of corrupt registry values such as empty keys, file path folders, Class IDs, Interface, Font references and many other similar and unwanted items you need a reliable and an effective registry repair too which can remove this stuff safely from the registry without affecting the system and other applications in the computer. There are many registry cleaner tools available online but not all of them are very effective and reliable. Most of them merely prove to be good but they really dont help much and they are ineffective. For the best one you can use do is to use the trial version of the software for some time and observe it then decide for the buy or using it.