Do a custom install and install each version in its own program folder to use multiple Firefox versions.

• Custom installation of Firefox on Windows

Create a new profile exclusively for each Firefox version and create a desktop shortcut with -P "profile" appended to the target to launch each Firefox version with its own profile.

See these mozillaZine KB articles for information:

• http://kb.mozillazine.org/Testing_pre-release_versions

• http://kb.mozillazine.org/Creating_a_new_Firefox_profile_on_Windows
• http://kb.mozillazine.org/Shortcut_to_a_specific_profile

• http://kb.mozillazine.org/Using_multiple_profiles_-_Firefox
• http://kb.mozillazine.org/Opening_a_new_instance_of_Firefox_with_another_profile

Thank you cor-el for those links! I have decided that I do not want to run Nightly anymore after reading that it could destroy my profile information or crash my computer.

Honestly, do you think Aurora will cause any damage to my profile if I use it with my day-to-day profile that contains all of my important information? Keep in mind I would be using Aurora on both computers that are set up to synchronize and then using Firefox 4 if ever needed. I've been running the betas for Firefox 4 and also using 3.6 when needed with my normal profile and there was never any corruption, so why would that happen with Aurora? Wouldn't Mozilla warn us? I do not want to set Aurora up to use a different profile. If that is dangerous, I will uninstall it and just use betas and final releases across my machines. But I would love to test the newest features and provide suggestions for improvement, but I need to use my same profile.

What do you suggest I do?

Thank you!

You should never use the same profile with different versions to prevent Firefox from initializing the profile after every switch. Test versions like Aurora (currently alpha 2) should be used with caution and for testing and not for daily usage with important things as you can never be sure if it works on all web pages. Those versions are updated daily and can break at any time, that doesn't happen too often and is usually corrected via a respin that backs out changes. Aurora should be more stable than the Nightly Firefox 6 builds.

In case you are still interested, you can keep an eye on the daily threads for the Nightly builds (The Official Win32 xxxx Builds are out) in the Firefox Builds forum on the mozillaZine site.

• http://forums.mozillazine.org/viewforum.php?f=23
• http://forums.mozillazine.org/viewtopic.php?f=23&t=2166731

The thing that disturbs me is that I used all 12 betas versions of Firefox 4 on both computers in conjunction with 3.6 when needed on the same profile with no problems at all. Then I switched to the RC and then the final, all using the same profile.

I had no idea corruption could occur by doing so and figured I could do the same thing for Aurora.

I understand Aurora may not be as secure as betas. If it is a bad idea to use the same profile for Aurora, are you also telling me that the profile could get corrupted if I use the beta versions?

Best to follow the advice that cor-el gave you. Just because you didn't have problems with mixing 3.6.x usage with the 4.0 betas, doesn't mean you won't have problems in the future - IMO you were extremely lucky. Alpha versions are more temperamental that beta versions are and can be broken on a daily basis in some respects. I have tested all the alpha versions since Firebird 0.7 in late 2003 and barely a week went by without something being broken for a day two. If you're using the same Profile for a release version and a "nightly" you risk breaking your Profile and having to create a new one anyways. IMO, makes more sense to be prepared for that situation than to whine about it happening when you knew about that possibility probability ahead of time.

Ok I have decided what I want to do across my two machines. I want to use my normal profile only with Firefox 4. But I also want to use Aurora and Nightly on their own new profiles just to see what's new and give suggestions when I have some spare time.

When the beta is released, I will most likely install it and use it with my normal profile and try never to use the final release of version 4. Hopefully I will be "lucky" just like I was last time with the 12 beta versions.

Thank you for the replies.

Please click the Helpful button next to the answer that solved your Firefox support issue, when you are logged in, so this thread gets marked as Solved.