It's one of those days, thanks to a hard disk going south I ended up having to rebuild the system drive on one of my machines. After putting the important software back on there - "Outlook and Emacs", as one of my colleagues calls it - I had to reapply some of the usual tweaks that make a generic developer workstation my developer workstation.
One of the changes I wanted to make was to have an "Edit in Emacs" type context menu in Windows Explorer. The only reason I was keeping another editor around was because it's a feature I use regularly but hadn't got around to setting up for Emacs.
StackOverflow to the rescue, as usual. I used the registry script provided in the first answer and tweaked it slightly. In contrast to a lot of people, I don't keep Emacs running all the time but only when I'm editing something. For that reason like my Emacs setups to either start a new instance if there is no Emacs running or use an existing instance as a server if there happens to be one running.
With my little tweaks to start an instance of Emacs even if there is no Emacs server running, this is what the updated registry script looks like:
Windows Registry Editor Version 5.00 [HKEY_CLASSES_ROOT*shell] [HKEY_CLASSES_ROOT*shellopenwemacs] @="&Edit with Emacs" [HKEY_CLASSES_ROOT*shellopenwemacscommand] @="C:\Tools\emacs\bin\emacsclientw.exe -a C:\Tools\emacs\bin\runemacs.exe -n "%1"" [HKEY_CLASSES_ROOTDirectoryshellopenwemacs] @="Edit &with Emacs" [HKEY_CLASSES_ROOTDirectoryshellopenwemacscommand] @="C:\Tools\emacs\bin\emacsclientw.exe -a C:\Tools\emacs\bin\runemacs.exe -n "%1""
There's another neat little tweak in there, too - the directory "C:toolsemacs is actually a symbolic link to the current installed version of Emacs on this machine so whenever I update my version of Emacs, I don't have to redo other scripts and settings that try to use the current version of Emacs.
This might be an old hat to most Unixheads, but it's slightly unusual on Windows so I figured I'll mention that it's possible to do something like this on Windows also.