Make sure that Firefox gets installed properly.
Open the DMG file and drag to Firefox program to the application folder on your hard drive.
You shouldn't double-click the Firefox application to run it from the disk image, but drag it out of the DMG folder instead.

• How to download and install Firefox on Mac
• http://kb.mozillazine.org/Installing_Firefox#Mac_OS_X

Clearly I'm a computer idgit. You tell me to open the 'DMG file'. I don't know what that is. Are you sure I have one? Sorry to be a pest. Bagwix

Clearly I'm a computer idgit. You tell me to open the 'DMG file'. I don't know what that is. Are you sure I have one? Sorry to be a pest. Bagwix

I'm baffled. You can't want me to go on repeating my reply. Putting it in different words probably won't help. So what do I do next? Bagwix

Round and round we go. You asked me to post a reply.How the hell do I ? Bagwix

Round and round we go. You asked me to post a reply.How the hell do I ? Bagwix

I give up

We are not around here 24 hours, so you may need to wait for a response.

The DMG (disk image) file is the Firefox installation file that you can download from the Mozilla site and save to your desktop. You can double click that file to open the image.

From How to download and install Firefox on Mac:

• Once the download has completed, the disk image may open by itself and mount a new volume which contains the Firefox application. If you do not see the new volume, double-click the Firefox dmg icon to open it.

• A Finder window appears, containing the Firefox application. Drag the Firefox Icon into the Applications folder.

Sorry if I sounded peremptory. My problem is, I don't talk computerspeak. I ask what a DMG is and I'm told I can download one from the 'Mozilla site'. Sadly I've no idea what the Mozilla site is. You'd better give up on me. Firefox has always seemed perfectly good to me, without sexy additions. Sorry to have been a pest. Bagwix

You can download Firefox via this Mozilla website:

• http://www.mozilla.com/en-US/firefox/all.html