You can do this by installing Firefox portable (http://portableapps.com), and install it to hard drive in a NEW location rather than a USB drive. Here is how I would do it (although you can tweak this to achieve want you want), leave your standard installation where it is. Clone the portable folder to second location. Copy your first profile data to portable folder "DATA" sub-folder as described on their website and copy your second profile to the the second new portable "DATA" sub-folder (the folder below the one containing FirefoxPortable.EXE). Start each FirefoxPortable.EXE and check it is customized correctly (eg. addons, plugins in the normal way etc). Optionally rename FirefoxPortable.EXE to FFP.EXE if you like short names :-) and setup two shortcuts to each of these portable installation folder's FFP.EXE. I have used V6.0 and V25.0.1 this way and worked fine.
Advantages
- You an run completely separate configs (they can even be different versions of Firefox if you desire). Yes it takes up more disk space as you clone firefox application but I find this easier to manage.
- I run about 30 addons and have had no issue with the portable version
- If you have a collection of active and inactive addons troubleshooting addon confilcts is easier. Just take a clone of the folder and use it for testing just a single addon switched on without messing up you main profile.
Issues (applies if Firefox is default browser)
- Leave you standard installation as is and set as default browser
- Leave your old standard installation with the profile manager prompt as the default. (In your case you could run this as your "general" profile with no prompting". Occasionally some application will try to launch this default browser when you are not expecting it (e.g. eg a chat client that opens URLs) and whenever you see the profile prompt just exit and start the correct portable version via shortcut
- Well now there are 3 versions for Firefox - which should it use for files? The solution is always start the Firefox from the shortcuts before opening *.url, *.htm[l], or *.mht and they will open in the active Firefox correctly.
- If you use firefox sync I would expect that you name each profile as a different "device name" for it to play nicely. For example syncing your bookmarks across all profiles.
- I do software updates manually I would recommend that.