Note: This page hasn't been updated in over a year, if you are running Firefox 2.0 or Minefield 2.0a1 you don't need anything more than a Command Line Switch of -no-remote to run MOZ_NO_REMOTE.
https://bugzilla.mozilla.org/show_bug.cgi?id=325509
In days gone by (Firebird/fox versions 0.8 and prior), Firefox power users were able to run multiple different installations without trouble as long as the executable files (firefox.exe) were re-named to something unique. This feat worked best (but not absolutely necessary) when the various installations, beyond the first, were launched with their own unique Profile.
With the arrival of the Firefox 0.9 version (in June, 2004), the parent.lock file was introduced to prevent a currently in-use Profile from being used by another process. Apparently this file also prevents multiple incidences of any Firefox executable from being launched irregardless of the name of the executable.
A Windows OS variable called "MOZ_NO_REMOTE" is the key.
The are two basic things that need to be done.
1) Invoke an environment variable called MOZ_NO_REMOTE.
2) Create desktop shortcuts that will start a specific Firefox installation with a specificProfileName
These methods have been tested in WinXP and W2K; YMMV with Win9x and ME.
The Permanent Variable version sets the variable within the OS thru the Windows Control Panel, allowing a 2nd (and subsequent) launch of a Firefox.exe process to ignore the presence of the parent.lock file. If the Permanent Variable is set thru the Control Panel and you try to open another instance of Firefox thru an external program (such as clicking a link in an email program or an instant messenger program) Firefox will bring up the Profile Manager dialog box. Double-clicking the Desktop Icon of an already lauched Firefox version/Profile to open another Firefox window will also bring up the Profile Manager dialog box.
The Batch File version doesn't have that limitation. The batch file sets the variable to 1, starts the new version/Profile, and then sets the variable back to zero. Because the variable is only set to one when you are starting a new version/Profile, external links (email prog or IM prog, for instance) will be unaffected and will not start the Profile Manager. If you have two or more versions/Profiles running simultaneously, external links will open in the most recently started version/Profile.
Thanks to Vectorscape (at the MozillaZine forums) for his expertise with regards to running Batch Files within Windows.
