You can delete that icon as it is not needed to operate FireFox...If you're not sure and don't like the idea of deleting it, keep it -- No harm or benefit either way... It takes up a very, very small amount of space on your hard drive and does not take away any memory or processing power.
How it got there without your knowing it is one of the big mysteries/secrets of Windows and Mozilla, with their biz-zillion lines of code and instructions that are designed to take over your machine...
If you just don't like looking at the icon on your desktop and don't want to "delete" anything, here's a couple of ways to go:
If the properties box identifies it as a short-cut, you can remove (delete) the short-cut from your desktop and the main folder will remain where Windows or Mozilla decided to have it reside. You'll never see it again unless you search for it. It will continue to be stored but will never be used...
And/Or
Whether it's an original folder icon or a short-cut icon, you can move it off of the desktop and put it into any folder you like - just right click it and select "Cut" , then open any folder and "Paste" (to move it to that folder). "Cutting and pasting" will still allow Windows or FireFox to access (find) it or operate the stuff that's in it if there's anything in the folder that's needed.
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