The windows system Registry has been called the most important part of any Windows PC operating system (OS), but you probably didn’t even know it exists. There is a good reason for that. Microsoft doesn’t want you messing with it. Like so many other features in Windows, Microsoft chose to hide information considered too powerful to be left in the hands of mere mortals. Only the wisest of gurus can be entrusted with such knowledge. The registry controls everything and a single mistake can have devastating consequences on the entire OS. Installed programs and applications will write important data into the registry. User defined data and configurations are also stored. The data is tracked through a tree of folders and it’s called “keys” that branch off the registry nodes. Every key can have sub keys nested in multiple levels. Its data known as “values” are stored in the keys and sub keys. Groups of related keys, sub keys and values are known as hives. Applications can modify the keys by changing the values, adding new keys or deleting existing ones. More recent versions of Windows will back up the registry and in the event of a problem, will ask you if you want to use the “Last known good configuration.” This was an option that began in the old Microsoft Windows vista days. The good news is that such configuration issues related to the registry will not affect your important data like documents, photos, etc. The bad news is that many times the problem that caused the crash in the first place may also be saved in the backup versions of the registry. Many software programs exist to examine registry the keys and make any necessary repairs. These programs can even check your registry for unused keys that clog your system. Removing these keys can significantly improve performance. For more information on the Windows Registry, check out the Microsoft software support program.