Registry errors occur for many reasons, including incorrect program installation / uninstallation, incorrect removal of software or corrupt hardware drivers, and orphaned startup programs. These Registry errors usually lead to slow unpredictable operation and can cause crashes for no reason, or PCs that refuse to startup at all.

If you haven't seen your computer crash and display Registry error message it doesn't mean that you don't have Registry errors on your PC.  First there's the matter of simple semantics: At one end of the spectrum, there are Registry errors that, if not corrected may make a system unbootable or unstable, or that may cause some of your software to crash or to malfunction.  Such Registry errors should be addressed then and there; otherwise the error messages might get you into worse conditions that might even lead to severe crashing.  It is always good to back up Registry and the whole system configuration before trying to fix the Registry errors.

Whenever a user makes changes to "Control Panel" settings, or file associations, system policies, or installed software, the changes are reflected and stored in the Registry. You can remove or correct Registry errors that may cause your computer to crash, and you can optimize the Registry's organization to speed it up.  Registry errors and corruption can prevent your system from running optimally or even booting.

By using PC tune-up utilities such as Registry cleaners regularly, your system will be more stable, your software will run quicker, and your operating system will boot faster.  The software scans every inch of your file system and Registry in a few minutes.  In most cases you will be able to restore any changes made using the software by choosing Restore Registry backup. This software will backup and restore files automatically and can secure all your most wanted files or hold back files in doubt. 

All you need to do is download Registry cleaner software, install it and periodically fix Registry errors.  To fix Registry error with the Registry cleaner you can download the software free of cost from most internet sources.  While opting for the download you need to be careful about the compatibility of the software with your system.  Apart from that, you need to make sure that the hardware configuration of your PC matches with the requirement of the software.  The software will delete all the unwanted and outdated entries, leaving the valid entries intact.