Click the Firefox button, go to Options | Options | General and in the Downloads menu, checkmark the radio button called "Always ask me where to save files". See screenshot.

Incidentally, some of your plugins are seriously out of date which exposes your system to exploits. Please visit the Plugins Check page and update where necessary.

Thanks so much Xircal, much appreciated and thanks for warning me re plugins

You're welcome.

Could you please click the "Solved It" button next to the post which solved the problem for you? This will help others searching for a solution to the same question.

Thanks.