Starting with Windows 95, the Registry is a database that holds configuration data about the hardware and environment of the PC. It is made up of the SYSTEM.DAT and USER.DAT files.
The Registry can be edited directly, but that is usually done only for non-published tweaks or as a last resort. Routine access is done via the Windows control panels and Properties menus. See Win Properties.
To get into the Registry, run the Registry Editor program (REGEDIT.EXE) from the Run command in the Start menu. The Registry contains five folders. In Windows 95/98, there is a sixth folder.
Contains file associations and OLE information. It shows exactly the same thing as the folder HKEY_LOCAL_MACHINE\Software\Classes.
The portion of HKEY_USERS that pertains to the current user. It contains the colors, fonts and attributes for the desktop environment as well as any network connections. If the current user is the only user of the system, HKEY_CURRENT_USER and HKEY_USERS are the same.
Contains the above information for all users of the system. It is the USER.DAT file.
Holds a large number of settings for the hardware, system software and applications. Install programs also create folders within this folder and place information in them, similar to the INI files that were introduced in Windows 3.1.
Contains settings for the current display resolution and printers.
Holds performance statistics that can be viewed in Windows 95/98 with System Monitor (SYSMON.EXE).
The "Handles to the Keys" (HKEYs) are the portals to all the configuration settings in a Windows computer.