Firefox reset: as of Firefox Version 39
- Open in Firefox, a new Tab with the key combination [Ctrl] + [T] and type in the address bar "about:support" (without quotation marks or spaces).
- Here, you can try on the right first, to start Firefox without Addons new. Often the common problems fixes.
- In the case of Adware and deeper Changes in the settings you should reset the Browser completely: to do This, click the "Firefox cleanup" (see image).
- The following query will confirm with clicking on "Firefox cleanup".

Reset Firefox (image: Screenshot)
After the Reset all the extensions and plug-ins are deleted. We therefore show useful Firefox Tools, you then be unable to go without. Should you individual help when you Reset the Firefox settings, then contact the experts in the CHIP Forum.