The registry is a hierarchical database that is used by the Operating System (OS) to store information that is necessary to configure the system for users, applications and hardware devices. It contains information that Windows continually references during operation, such as profiles, applications installed on the computer and the types of documents that each can create. It also contains information for property sheet settings for folders, application icons, hardware that exists in the system, and the ports that are being used (”Windows registry”).
The Registry replaced most of the text-based .ini files used in Windows 3.x and MS-DOS configuration files, such as the Autoexec.bat and Config.sys. You can edit the registry by using Registry Editor (Regedit.exe or Regedt32.exe). But be careful if you use Registry Editor incorrectly, you can cause problems that may require you to reinstall the operating system (”Windows registry”).
The Windows Registry is split into five logical sections. These all begin “HKEY” (an abbreviation for “Handle to Key”). Each of these keys is divided into subkeys, which contain further subkeys, and so on (see table 1). Any key may contain entries with various types of values. The values of these entries can be: a String Value, a Binary Value (0 or 1), a DWORD Value (32 bit unsigned integer), a Multi-String Value, or a Expandable String Value. Registry keys are specified with form similar to Windows’ path names, using backslashes to indicate levels of hierarchy. E.g. HKEY_LOCAL_MACHINE\Software\Microsoft\Windows refers to the subkey “Windows” of the subkey “Microsoft” of the subkey “Software” of the HKEY_LOCAL_MACHINE key (”Windows registry”).
