I have 2 firefox account have to use both without mixing informations in one bro...

Hi Am.Shekari, if you each log in to Windows under your own Windows user account, you should be starting up Firefox in a separate Windows user profile and zero mixing should occur. Problems arise when you share the same Windows user account with someone else, because Firefox will default to using a single settings folder (Firefox profile folder) every time, regardless of who is at the keyboard.

Option #1: Always use a personal Windows user account (fast, easy)

Option #2: Share a Windows user account, but create separate Firefox profiles and personal shortcuts to launch them (quite a bit of work)

Option #3: Run two different flavors of Firefox to keep things distinct automatically (easy, but slightly less stable)

If you don't want to take advantage of Windows user account switching, here's what you need to do. But first, some background:

Profiles vs. Accounts

Firefox Accounts share whatever data you have in your running installation of Firefox with other installations where you use the same account. You want to only sign in to your Firefox Account where you WANT to combine data.

Since each profile has separate data to start with, you can keep them separate by only using a different Firefox Account with each profile where you want data to stay separate. Make sense?

Remember: the profile is the boss, and Firefox Sync is a service you can use to merge data with your currently running profile.

Creating a New Profile

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

Take a quick glance at the page and make a mental note of which Profile has this notation: This is the profile in use and it cannot be deleted. That is your current default profile -- the one that loads at startup and the one that Windows uses to open shortcuts/links from other applications.

Click the "Create a New Profile" button, then click Next. Assign a name like Mom, ignore the option to relocate the profile folder, and click the Finish button.

Firefox will switch your default profile to the new one, so click the Set as Default Profile button for your regular one to avoid an unwanted surprise at your next startup.

Scroll down to Mom and click its Launch profile in new browser button.

Firefox should open a new window that looks like a brand new, uncustomized installation. (Your existing Firefox window(s) should not be affected.) Firefox will suggest connecting to a Sync account -- you should only connect to Mom's account in this Mom profile, or leave that for her to do.

Meanwhile, your regular profile is still running in other Firefox windows, so it's a good idea to use a different theme to keep them straight. This article has more info on themes: Use themes to change the look of Firefox. Hopefully you can find something to match Mom's taste.

And then you're done with creating the profile. You can close Mom's window.

Option #2 vs. Option #3

With Option #2, the next step is to set up desktop shortcuts that you and Mom will need to remember to use to start Firefox so you don't end up in each other's stuff. With Option #3, you would install a different flavor of Firefox such as the Developer Edition (based on the beta, but carefully designed not to trample on profiles in the regular release of Firefox).

Option #2: Setting up Shortcuts

You can create desktop shortcuts to start up Firefox in a specific profile. Running Firefox this way can have a slightly unpredictable side effect related to your default profile and external links. It would be simplest if you never have both profiles running at the same time and try to open an external link.

To create a Windows shortcut:

• right-click the desktop > New > Shortcut
• the path usually would be along these lines for the Mom profile, but you should check the location of your Firefox program:
  "C:\Program Files\Mozilla Firefox\firefox.exe" -P Mom
• on the next panel, the name can be whatever you like

You'll also need to create one for your profile, whatever it is called.

Option #3: Setting up Developer Edition

You can install this program from: https://www.mozilla.org/firefox/developer/

Developer Edition will create its own profile, so in order to assign the correct profiles to the regular release and DE, here's what you do:

(A) In the regular release, on the about:profiles page, use the "Set as Default Profile" under the Mom profile to make that the default. Then close out of your profile.

(B) In Developer Edition, open about:profiles, then make your regular release profile the default profile for DE. After you exit and start it up again, it will upconvert your profile.

Since Developer Edition has a blue fox icon, it should be easy for both of you to avoid using the wrong one.