The main reasons of crashes, slowness and instability of Firefox are due to some extension that has a memory leak bug, toolbars that are installed without your knowledge, and more. However, finding out the main culprit is a time consuming and painstaking process.
But by implementing the new reset button to Firefox, Mozilla make things much simpler. Just clicking the reset button will create a new Firefox profile with default settings and migrate your bookmarks, passwords, cookies and form data. It means you will have a brand new Firefox installation without the penalty of losing all your data.
Unfortunately, the new reset button is not at an easy to access location. You have to go at Help –> Troubleshooting Information (about:support) to access the button. However, Mozilla will prompt users the option to reset Firefox when it crashes on startup for the third time. [via]
