Command Completion Character

(Snippet from Microsoft Site)

To Activate Automatic Completion Permanently loadTOCNode(3, 'summary');
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

1. Click Start, click Run, type regedit, and then click OK.
2. To enable automatic completion for the computer, locate and click the HKEY_LOCAL_MACHINE\Software\Microsoft\Command Processor key.
3. To enable automatic completion for the current user, locate and click the HKEY_CURRENT_USER\Software\Microsoft\Command Processor key.
4. For folder name completion, double-click the CompletionChar value. Type in hexadecimal the control character that you want to use. For example, if you want to use the TAB key as the control character, the control character is 0x9 (type 9 as the value; Windows converts it to hexadecimal). If you want to use the same control characters that you use for a single command session, type 0x4 for CTRL+D and 0x6 for CTRL+F. You can use the same control character for both folder and file name completion.
5. For file name completion, double-click the PathCompletionChar value. Type in hexadecimal the control character that you want to use.For example, if you want to use the TAB key as the control character, the control character is 0x9 (type 9 as the value; Windows converts it to hexadecimal). If you want to use the same control characters that you use for a single command session, type 0x4 for CTRL+D and 0x6 for CTRL+F. You can use the same control character for both folder and file name completion.
6. Quit Registry Editor.If you enable this feature for the computer, the feature is available to all users. However, you can deactivate the feature for any individual user, or you can use different control characters for that user than you applied to the computer. The user settings take precedence over the computer settings.