Registry

The registry is a system-defined database in which applications and system components store and retrieve configuration data.

The registry was first included as part of Microsoft® Windows® 3.1 to address problems inherent in the system configuration storage mechanism of earlier versions of Windows. Before Windows 3.1, the Windows operating system used Win.ini and System.ini files for this purpose. In addition, applications could create and maintain their own .ini files. All .ini files were ASCII text files, which anyone could read and edit.

Some of the most important problems with storing system information in .ini files are the following:

• The fact that anyone could access and change these files meant that the integrity of the information contained in the files could not be guaranteed.
• No rules governed what could be added to an .ini file or where it could be located, so it was hard to find or change an item. This is also related to the first problem: if someone edited an .ini file, an application not capable of dealing with edited .ini files would not be able to retrieve the necessary configuration information.
• Each .ini file was strictly limited in size to 64 KB. One solution was to have private .ini files, but this caused problems with sharing data for applications that were using dynamic data exchange (DDE) or OLE.

The registry database included with Windows 3.1 is the basis of the registry now implemented in both Microsoft® Windows NT® and Windows 95.

• About the Registry
• Using the Registry
• Registry Reference