Hi Frogman2014,

start the task manager and kill the "firefox.exe" process.

Ctrl + ALT + DEL -> tab process -> search firefox.exe

And dude, clean your history :D

Could you please explain how I start task manager. It is not on the toolbar

Hi Frogman,

If you are running Windows 7, press Windows key + R and type taskmgr.exe from there, click the processes tab and then click on firefox.exe then click end process

Does that help?

You can remove all data stored in Firefox from a specific domain via "Forget About This Site" in the right-click context menu of an history entry ("History > Show All History" or "View > Sidebar > History") or via the about:permissions page.

Using "Forget About This Site" will remove all data stored in Firefox from that domain like bookmarks, cookies, passwords, cache, history, and exceptions, so be cautious and if you have a password or other data from that domain that you do not want to lose then make a note of those passwords and bookmarks.

You can't recover from this 'forget' unless you have a backup of the involved files.

It doesn't have any lasting effect, so if you revisit such a 'forgotten' website then data from that website will be saved once again.