Memory usage was only 1.3 GB with 1 firefox.exe running at Task manager. But it is slow and dragging. While the 4 firefox.exe which uses over 2 GB was much faster.

So your running 4 separate install of FF? Your response is confusing here?

Sorry to cause the confusion, there was 4 firefox.exe running in the process page/Task Manager, and now there is only one left then firefox became very slow and lagging.

Auto update was disabled. Firefox version 56.0.1 64bit.

Of course there is only one firefox.exe on the window. Similar to chrome, with many chrome.exe in the process page/Task Manager when it is running.

Similar to chrome, with many chrome.exe in the process page/Task Manager when it is running.

What version of Windows are you running?

Firefox running on windows 7, i5 2450m

As to the disappearing processes (e10's) that needs to be done in about config. I would think some corruption has happened. In 56 your unsupported and insecure and this function of Firefox is not completely turned on till ver 57. Ver 58 brings multi-thread processing to 57's multi-processors using all cores up to 4 instead of default prior of 1.

Suggest you update to ver 57.0.4 https://www.mozilla.org/firefox/all/ as it also just got a security update for the Meltdown issue : https://www.theguardian.com/technology/2018/jan/04/meltdown-spectre-computer-processor-intel-security-flaws-explainer

You could try a refresh to see if that fixes the issue : Please Refresh but do this 1st: Delete your Cookies and Cache and TEST.

• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer
• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

then

• https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings

TEST....... If no issues then Extensions which need to be added back in 1 at a time and tested ..... Or it is your Profile : Make a new one and test ...:

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

If is your Profile :

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Note: Any customization will revert back to default, you will also need to reinstall Extensions.

Is there some reason you are not updating to ver 57 ? Can find addons/Extensions here : https://addons.mozilla.org/en-US/firefox/addon/theme-font-size-changer/ Use Search. You can create and change Firefox in unlimited ways using: https://www.howtogeek.com/334716/how-to-customize-firefoxs-user-interface-with-userchrome.css/ Some lists can be provided. Please let us know if this solved your issue or if need further assistance.

Thank you for your prompt and detail support, But after the updater to 57, i find the bookmark tool bar fit less icons, the tabs are dark and square and ugly then the bookmark folder is now grey and not visible and I don't know what else had changed. Now i have to waster my weekend to search and do all the fixes, to change the folder color from grey to yellow seems an impossible task for me as i am not a tech guy, if there is an easier way pls tell me. As i have to work with the computer everyday, i find it very uneasy for my visions to adapt to this new environment, which did not improve the performance and find it very disturbing and annoying. Which is the main reason my auto update is ALWAYS off.

Is not hard code is around for everything is copy and paste and reading.

• https://www.howtogeek.com/333110/how-to-customize-firefox-quantum-and-remove-the-white-space-around-the-title-bar/
• https://www.howtogeek.com/333110/how-to-customize-firefox-quantum-and-remove-the-white-space-around-the-title-bar/
• https://www.howtogeek.com/333230/why-firefox-had-to-kill-your-favorite-extension/
• https://addons.mozilla.org/en-US/firefox/addon/theme-font-size-changer/

Reason why was a forced update as has to do with the Intel and other chips and the security vulnerability that has been on the front page of every news site the last several days. Mozilla is doing it's part in mitigating any attacks with the update :

• https://www.theinquirer.net/inquirer/news/3023893/opera-mozilla-vivaldi-and-more-rush-to-patch-spectre-and-meltdown-security-holes
• https://www.cbsnews.com/news/spectre-meltdown-intel-arm-chip-security-flaw-computers-phones-at-risk/
• https://www.cbsnews.com/news/what-intel-amd-chip-flaws-mean-for-you/

Also there was Windows Updates released on the 4th to, and they are doing their part in also mitigating the situation. I hope you have checked your Windows for out of sequence update. Search out Intel this week for software patches for your chip, AMD has issues also, your cell phone, laptops, notebooks, everything.

fyi: for the future :

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer

USSER CHROME LINKS http://techdows.com/2017/09/classic-theme-restorer-userchrome-css-modify-firefox-57-photon-ui.html https://github.com/Aris-t2/CustomCSSforFx/issues/1 https://www.accessfirefox.org/Theme-Font-Size-Changer.php https://www.userchrome.org/ https://www.accessfirefox.org/Firefox_Accessibility_Themes.php https://www.userchrome.org/what-is-userchrome-css.html http://kb.mozillazine.org/UserChrome.css https://github.com/axydavid/FirefoxUI/blob/master/README.md https://github.com/wilfredwee/photon-australis https://www.reddit.com/r/FirefoxCSS/ Note not all code in one place.

Please let us know if this solved your issue or if need further assistance.

In windows, grey is the color that use for disabled items, pls change it back to yellow.

Thank you for the support, The square tab makes it very difficult to tell which one is in use, Is there an easy way to change back the curve like .56?

Thank you very much for you assist and support.

I have a short message to browser developers ;

After the update, pls leave an option for users to switch back to whatever they are comfortable with. Some of the updates may be good but can be unacceptable as users had acquainted and may find it very irritating to adapt to a new environment. Some us of had worked all week and have no time to learn, research and recalibrate our browsers. I guess we would rather welcome a more 'user friendly' environment.

Firefox is a free browser. It is not yours. Also Security Updates must be implemented as per everyone else for  : http://money.cnn.com/2018/01/04/technology/spectre-meltdown-cpu-flaws-explainer/index.html Windows has a update for this also as does every other browser. Will need to look for info to fix your cell phone/laptops/tablets/everything. Intel & AMD will have to look next week for patches. Please make sure you are running Firefox 57.0.4 Windows 10 does not ask anything, it updates when it wants and gives tons of stuff do not need or use. Think you need to get use to the idea that times have changed as to what you think is yours.

I have already provided you with the information to change the color of the folders please read all that I asked you to. To achieve this is through a userChrome.css file in your profile which is able to style all elements of the browser. the second example at https://www.userchrome.org/what-is-userchrome-css.html covers colouring the bookmarks folder. and more information about how to create/use that file is available at https://www.userchrome.org/how-create-userchrome-css.html

Please let us know if this solved your issue or if need further assistance.

I think what eng5841 is saying is that it would be nice if Firefox could make its security updates without changing the look of everything on the browser. I too wonder why they feel they need to change the way the browser looks when they are fixing security issues.