Sometimes I have files that I want to open with Emacs, but I haven’t set the program to open to Emacs (for example, a log-file or .emacs). I found a nice hack for Windows machines in the internet (http://www.johndcook.com/emacs_windows.html#explorer).
Just create a file emacs.reg with the following text and adjust the path to your settings.
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\*\Shell\Open In Emacs\Command]
@=”\”C:\\bin\\Emacs-23.1\\bin\\emacsclientw.exe\” -a \”C:\\bin\\Emacs-23.1\\bin\\runemacs.exe\” \”%1\””
Before you double click on this file, save your registry (you never know…). After double clicking you will have a extra option in your right-click menu in your explorer, which starts Emacs, if Emacs is not running and start the client if it is already running.