The name of the executable file that is associated with a given filename extensionThe registration database is a systemwide source of information about applications. This information is used to support the integration of applications with Windows File Manager and is used by applications that support object linking and embedding (OLE).
An application can use the registration database to store the following information:
The name of the executable file that is associated with a given filename extension
The command line to execute—or dynamic data exchange (DDE) messages to send—when the user opens a file from Windows shell applications (File Manager or Program Manager)
The command line to execute—or DDE messages to send—when the user prints a file from File Manager
Details about the implementation of OLE if the application is an OLE server
The registration database is a standard part of Windows version 3.1. Any Windows version 3.0 application that supports OLE also uses the registration database. The registration database is not meant as a place for applications to store private data. Applications should use private initialization files for data that is not defined or that is not needed either by the Windows 3.1 shell applications or by OLE applications.
For most applications, the developer uses Microsoft Windows Registration Editor (REGEDIT.EXE) to edit the registration database and produce a registration (.REG) file that contains readable text strings corresponding to database entries. This .REG file can be merged into the user's registration database when the application is installed. For more information about merging text files with the database, see Section 7.1.2, “Format of Registration Files.”