You can view this Mozilla help article.

Try defragmenting your computer's hard drive(s). I recommend using Auslogics Disk Defrag Free.

WARNING: Always use caution when downloading content from the internet. I will take no responsibility for any damage caused by a download. Download at your own risk!

Would defraging help, because I/E Browser works fine?

Defrag the computer, and if needed create a new profile.

• Profile Manager - Create, remove or switch Firefox profiles

I would also use Defraggler instead.

• https://www.piriform.com/defraggler

Instead of Auslogics.

Why wouldn't I use the one installed on my computer? my

One cause of terrible performance and script errors on sites that use media can be the Flash Player plugin's protected mode. If you haven't already, please disable that. See this support article from Adobe under the heading "Last Resort": Adobe Forums: How do I troubleshoot Flash Player's protected mode for Firefox?

Defragging your computer would help.

You can think of it like this. Every time a new file is added to your computer, it is assigned a number in the order that it arrives. This means that when you run a program, your computer needs to look through every single file one-by-one in order, until it finds all files that it needs to open the program. This can cause a program to run slowly.

When you defrag your computer, your computer does two things. It groups program files together and assigns them consecutive numbers. It also re-arranges the ordering of the files and assigns them new numbers. The files that are used most often are numbered first compared to rarely used files.

This is why Internet Explorer does not run as slow as Firefox. Internet Explorer comes with the Windows operating system and is numbered first. Firefox however, is not numbered first like IE.

I have SSD's - defragging isn't an option