That's very suspicious!!

One possible explanation is that you are visiting a site with ads that pop up that page. Sometimes called "malvertisements."

Another possible explanation is a bad add-on.

A less likely possibility is that another program on your computer is sending URLs to Windows to open in your default browser.

Let's check the add-ons. You can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either:

• Ctrl+Shift+a (Mac: Command+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• type or paste about:addons in the address bar and press Enter/Return

In the left column of the Add-ons page, click Extensions. Then cast a critical eye over the list on the right side. Any system extensions that Firefox installs on its own are hidden from this page, so everything listed here is your choice (and your responsibility) to manage. Anything suspicious? If in doubt, disable.

Sometimes a link will appear above a disabled extension to restart Firefox before the change takes effect. You can complete your work on the tab and click one of the links as the last step.

Any improvement?

Hi

Thank you for your advice i also found that if i block the web site using an add on blocksite that works it stops it or it try,s to open but is promptly killed off by the add on

not a perfect solution but it works

Another way out of the trap is to (force it if needed) Close Firefox. Wait about 20 seconds for Firefox to finish closing. Right-click on the Firefox icon and select Open New Window. +++++++++++++++++++++++++++++++++ Sometimes this works. If it opens, close it by Menu > File > Exit. This will flush out that web page from the Session Store.