Change 'When Firefox starts' from 'show my windows and tabs from last time' to another option under General.Tap on the Alt-key to bring up the menu.You only can know which tab you remove recently by dialling 4636 in dialpad. There is an even easier solution to this, but it would have the consequence that you disable the session restore feature. You can not recover any tab that you closed. Note: Firefox seems to clear those recovery options only when you close the browser, but not while it is still running (if you set it to 0). Then again, it may be time to create different user accounts for the different users on the computer to avoid this from happening in first place. If you share the browser, you may want to consider disabling the feature, as other users may use it to restore tabs that you have closed even if you have deleted the browsing history. If you find yourself in situations where you need to restore tabs exceeding the 10 tab limit that Firefox normally uses, or windows exceeding the 3 window limit, then you can increase that to adjust so that it fits better with how you use the browser. If you are logged into Google Chrome, you may see recently closed tabs from other connected devices. This will only clear the recently closed tabs associated with this specific computer. It's a good idea to close all the current web pages, before restoring a group of tabs.

It is obviously possible to increase the values, which is fine if you are the sole user on the computer or if user profiles are used to distinguish between accounts. The recently closed list for your computer will now be cleared. Quick Tip: Tabs you restore will open next to the tabs already open on the browser.

How to get rid of recently closed tabs