You can only open one instance of Firefox if you start Firefox normally.

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

• 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/Bypassing_the_Profile_Manager

Use the -no-remote command line switch to open another Firefox instance with its own profile and to run different Firefox instances simultaneously, but do not use -no-remote with the default browser and the default profile.

• http://kb.mozillazine.org/Opening_a_new_instance_of_Firefox_with_another_profile

Set in the profile manager which profile to use by default if you click a link in an external program to make sure that the default browser opens with its own profile.

Thanks for the reply:) But I am confused. If I want to be able to launch each FF version separately then I use the "open a new instance" link? So I open Aurora (default) profile manager and make a new profile and name it Mozilla Firefox 16? I added the 16 to the shortcut for my install of FF 16 for easy recognition. Then append the shortcut for Mozilla Firefox 16 with the -P ?

Sorry for making this difficult. I guess I need a picture.

Why do you want Firefox 16? It isn't supported, insecure, and hardly used anymore.

Tyler, I think he/she is referring to Firefox 26.

I meant FF 19.. All the builds after 19 do not allow me to open multiple tabs (5 or so) without horrid slowdowns. Yes I have completely uninstalled FF etc.

Don't install such old versions of Firefox, they are soo horribly insecure. we can help you speed up your Firefox, just don't install anything that old.

Do tell. And how will you speed it up? I have followed all the "suggestions" already. Nothing has worked.

Try disabling graphics hardware acceleration. Since this feature was added to Firefox, it has gradually improved, but there still are a few glitches.

You might need to restart Firefox in order for this to take effect, so save all work first (e.g., mail you are composing, online documents you're editing, etc.).

Then perform these steps:

• Click the orange Firefox button at the top left, then select the "Options" button, or, if there is no Firefox button at the top, go to Tools > Options.
• In the Firefox options window click the Advanced tab, then select "General".
• In the settings list, you should find the Use hardware acceleration when available
• Now, restart Firefox and see if the problems persist.

Additionally, please check for updates for your graphics driver by following the steps mentioned in the following Knowledge base articles:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

• Upgrade your graphics drivers to use hardware acceleration and WebGL

Did this fix your problems? Please report back to us!

Thank you.

Done all that multiple times. Hardware acceleration on/off makes no difference/ Nvidia card is GTX470 with latest drivers. Have tried multiple drivers. As I said I have tried all the suggestion in this forum. You know the stock answers that are provided. Uninstall reinstall no addons etc.. And none of it works. How do I uninstall "ALL" remnants of firefox. I will start from scratch for the 20th time... Last effort. I have used FF for years and this is getting old. Chrome is where Im headed if it wont work after next reinstall. I should be able to open tabs without slowdowns. And by the way I notice that this is a persistent problem as of late with many besides me.

Try to create a new profile as a test to check if your current profile is causing the problems.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer some files from an existing profile to the new profile, but be careful not to copy corrupted files.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Hi I guess I wasnt explicit enough. I have done that. I have made a test profile on each reinstall. The same problem is encountered with a clean install or a new profile. A complete reinstall would also accomplish that I presume.

How do I get rid of "ALL" remnants of firefox?

Firefox will be in three main places on your computer.

1. The registry entries.
   Uninstalling Firefox from the control panel should sort out most of that. Manually editing the Registry is an option but can have serious unintended consequences.
2. The program folder.
   That contains most of the Firefox folders and files. To do a clean uninstall (and potentially a reinstall) you do need to delete these folders.
3. The profile.
   Firefox tries to retain this. Back this up if you wish to be certain you do not loose things like bookmarks and passwords. This is normally not removed, unless you use an option to remove personal data. If you are migrating to another browser you probably will at least wish to export bookmarks as HTML before uninstalling Firefox.
   • Export Firefox bookmarks to an HTML file to back up or transfer bookmarks
   • Back up and restore information in Firefox profiles

• Uninstall Firefox from your computer

Note that the profile appears in two locations: the main profile folder in AppData\Roaming and the cache folder in AppData\Local

• http://kb.mozillazine.org/Profile_folder_-_Firefox

Your link about the location of the profile folder does not work.

see - Profiles - Where Firefox stores your bookmarks, passwords and other user data

for the profile location

Ok Ive uninstalled all pieces. I reinstalled the latest FF. When it started the profile manager came up (never seen it do that before) and asked me to pick a profile. But there is no profile yet. So I tried to make a new one. It then throws up an error.

"Completing the Create Profile Wizard If you create several profiles you can tell them apart by the profile names. You may use the name provided here or use one of your own. Enter new profile name: Default User Your user settings, preferences and other user-related data will be stored in:

C:\Users\Lewlew\AppData\Roaming\Mozilla\Firefox\Profiles\ygmtb8cf.Default <file://C:/Users/Lewlew/AppData/Roaming/Mozilla/Firefox/Profiles/ygmtb8cf.Default>User Choose Folder... Use Default Folder c] [DefaultBox] Profile Creation failed [#] Profile couldn't be created. Probably the chosen folder isn't writable. J-i [Exception... "Component returned failure code: 0x80520012 (NS_ERROR_FILE_NOT_FOUND) [nsrToolkitProfileService.createProfile]" nsresult: "0x80520012 (NS_ERROR_FILE_NOT_FOUND)" location: "JSframe :: chrome://mozapps/content/profile/createProfileWizard.js:: onFinish :: line 196" data: no]

Mozillazine google cached

• http://webcache.googleusercontent.com/search?q=cache:SaPbrT4kthcJ:kb.mozillazine.org/Profile_folder_-_Firefox+&cd=1&hl=en&ct=clnk&gl=uk

Initially delete the -P on your shortcut. Firefox should then start normally without the profile manager coming up. Firefox should create a profile if a profile or profiles-ini file does not exist.

Afterwards add the -P back on to the shortcut so that you can use the profile manager.
CARE

• unless you fully understand the intricacies do not delete or rename profiles
  • I suggest using shortcuts to start Firefox, just remove the unwanted shortcuts
  • probably best to go with suggested locations, but also note it is always best if folders used are empty ones