The registry system

In Windows, the registry is a common database that contains system-wide configuration and application settings.  Examples of stored information in the registry are as follows:

• Associated programs that execute specific files:
  • DOCX files are associated with Microsoft Word
  • PDF files are associated with Adobe Reader
• Associated icons to specific files and folders
• Software settings:
  • Uninstall configuration
  • Update sites
  • Ports used
  • Product IDs
• User and group profiles
• Printer setup:
  • Default printer
  • Driver names
• Designated drivers for specific services

The registry is stored in hive files. The list of hive files is also found in the registry itself, as can be seen in the following screenshot:  

Writing and reading information from the registry requires using Windows registry APIs. The registry can be viewed visually using the Registry Editor. Entries in the right pane of the Registry Editor are the registry keys. On the left pane, the registry values are found under the Name column, as can be seen in the following screenshot: