This method was tested using Vim 6.2 on Win2K and Vim 6.1 on Win98. Also using Vim 7.3 on WinXP. Within the registry, you can specify the source editor to be used by Internet Explorer when View|Source is selected. Unfortunately, you can't specify a quoted filename argument here, i.e. "%1". The editor specified is supposed to handle filenames which contain spaces. This will cause problems for Vim because Vim treats each space as an argument separator. If an unquoted filename contains spaces, Vim treats the filename as multiple arguments and will open multiple files instead of one. To workaround this problem a quoted filename has to be passed to Vim. This can be done by creating the following Visual Basic Script file gVim.vbs: