What is the registry and how does it work?

The registry is the memory of every Windows computer. All system-relevant information is stored and called up here. We explain what happens in the registry in our practical tip.

Windows registry - what is it?

• The registry, or registry database, is a central configuration database for Windows.
• Information for Windows and programs installed on it are stored in the registry.
• This way the software knows how to behave. For example, autostart programs are stored in the registry that are started automatically when Windows starts.
• Programs also store information in the registry. Word, for example, stores information about recently opened files in the registry.

How is the registry structured?

The Windows registry has existed since 1993 when Windows NT was introduced. For the first time, all information was saved in one place. Previously, the data from each program was saved in individual text files. With increasingly complex structures, however, sooner or later this leads to chaos.

• The registry consists of seven files: six of them are stored in the Windows folder on the hard drive, the seventh contains information about the user account and is located in the corresponding folder.
• The structure of the registry is similar to the folder structure in Windows. Instead of folders, there are so-called keys. There are no files in the keys, but entries that contain the information in text or number form.
• The registry contains about 200, 000 entries, and many more with many installed programs.
• Still, the files don't take up much space. Information is stored in the form of simple codes, so the files only come to around 100 to 200 Mbytes.

How does the registry work?

• Information can be stored as text, so-called strings. For example, the start page is stored in your browser.
• Settings of programs or Windows are usually stored in numbers. Instead of storing complex program codes in the registry, only the information about which program codes Windows should execute is stored here.
• Install a program, it creates one or more keys in the registry. Start the program and make settings, they will be stored in the registry so that the settings are still available the next time the program is started.
• Unfortunately, when you uninstall programs, not all entries in the registry are always deleted. This creates an ever increasing amount of data that you should clean up every now and then so that Windows can work faster. The free tool CCleaner is suitable for this.