If you mean things such as YouTube videos, try Download Helper. It works for me.

There are a plethora of extensions that allow you to download videos from your favorite sites. If you need help with any extension, you will need to contact the developer.

Search for "video download"

No I meant the download button that is usualy on the top bar, and the same applies to clips or any download.

I have solved my problem.. I downloaded Ant.com as an add on. many thanks for all the suggestions.

When you clicked on this download button, did it bring up the download status window? If so, you may need to customize your toolbar. See How do I customize or rearrange toolbar items? Drag the "downloads" icon into the desired location on your toolbar. Also see Navigation Toolbar items. Let me know If I am mistaken.

Did you previously have the download button from the ant.com toolbar (the one you said was missing) or did you download it to compensate for the lost download button?

Yes it does bring dowen the download status window but I have no problem with that

I downloaded Ant.com, and this gave me the button that was missing.

Firefox has that feature built-in. Furthermore, the ant toolbar is known to cause some problems including stability. If you want to know how to get the download button without the toolbar, see my second post. If you now want to uninstall the toolbar, look at Uninstalling Add-ons.