Can I run Firefox 3 and 4 at the same time?
I've seen variations on this questions, but they typically ask whether it's possible to have both 3 and 4 installed and switch between them (the answer to which is to use profiles). My question is: can Firefox 3 and 4 be running at the same time? When I try to run Firefox 4 when 3 is running I get a message that Firefox is already running. I haven't tried the profiles solution, so if that solves everything, that's good, and apologies for asking again.
I want both running at the same time so that I can compare them, copy tabs between them, and see whether 4's new features can organise what I do better, whether the missing plugins hurt, and so on. I like the idea of starting a new profile and copying to it because I accumulate a lot of bookmarks and tabs, and copying them over manually is likely to filter them and introduce some order.
Semua Balasan (5)
The answer is to use profiles. As for copying bookmarks, especially if there are a lot then it may be easier to use the library feature of firefox to sort your bookmarks, rather than to copy induvidual bookmarks.
Do take care to backup bookmarks manually, it is all too easy to overwrite the wrong set. (or use a backup utility) Remember also if you use the new sync feature it is rather an all or nothing affair, it is not designed to run multiple differing sets of bookmarks, it is designed to keep the bookmark sets the same on multiple machines..
Firefox will need to operate with different profiles, but the 'no-remote' option is what you are needing if you want two separate firefox profiles open simultaneously. See
Having now tried to run 3 and 4 alongside each other, I'll suggest to people not to try it. It's barely possible, but is more trouble than it's worth. For one thing running 4 caused my icon order to change in 3, with the stop and reload buttons moving to the right of the address bar. 4 also somehow became my default browser even though I specifically told it no, which meant that it took over my 3 profile, opening the tens of tabs I have open without having Bar Tab installed, which was a little bit of hell. I ended up uninstalling it.
Firefox 4 isn't bad, and there are things I like about it (in particular the pinned app icons) but Tab Mix Plus doesn't work well with it, and some other extensions I use, so I will wait until they do.
I wonder if the problem was that you did not successfully manage to keep the profiles separate, but inadvertently for instance started firefox 4 without forcing it to use its own separate profile.
You need to make sure that you start each version with its own profile.
You can do that by adding the profile name as seen in the Profile Manager to the command line in the desktop shortcut:
"C:\Program Files\Mozilla Firefox\firefox.exe" -P "profile_name"
It's very possible that the problem (or part of it) is that Firefox 4 launched with the other profile, since this did happen. From my experience it's not easy to avoid, or at least not obvious. The problem is that the process in unforgiving, and if you launch at the wrong time (for example with the profile manager still running) or make a mistake in the link, you're instantly screwed. Which is why I think it's not recommended to attempt this. These browsers are just not made to run alongside each other. It's not impossible to achieve, but there's need to be very careful while using them.
I did my test, saw that the plugins I want don't work right, went back to 3. It's a little screwed up, but just a little. I'll live with it.