I doubt that it is possible to have two versions of Firefox at the same time, but not 100% sure.

For security reasons alone (important!), it is strongly advisable to use the latest stable release. There are often ways of changing default settings so that newer versions can match some of the viewing properties of older versions. It's possible that you might be able to assign your keyboard's zoom button to the Firefox text control.

Change is inevitable Fran. Some of it you can adapt to your needs, otherwise you must adapt to it. The more you know, and the more people you can get onside to help you, the more control you have and the better you can cope.

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