Using your file browser, look for Firefox in c:\Program Files (x86) after, look in the other Program Files (x86)

Once you find it, right click Firefox.exe and create a shortcut. Move it to your desktop. Does this work?

Note: In creating shortcuts, there can be no spaces. Instead of using; c:\Program Files (x86) you must use; "c:\Program Files (x86)"

If you use the full, offline installer - https://www.mozilla.org/en-US/firefox/all/ - you should be able to do a Custom installation to the D:/ drive. Otherwise I don't think the "stub" offers the Custom option - but I not 100% sure of that. I have never used the "stub" and always do a Custom installation so I can edit the folder name to include the Firefox version number, at least the number if not other identifiers. How you got - D:\Program Files (x86)\Mozilla Firefox\firefox.exe - is unknown if you did a "routine" installation.

But the "bulk" of what Firefox does /saves / uses - the Firefox Profile - will be on the same drive as Windows 7 in the Roaming and Local folders hierarchy, regardless of where Firefox program files are installed. So if you are looking to reduce wear and tear (theoretical with early SSD drives) on that SSD, using Custom alone won't "move" the Profile and what Firefox "writes" to. That can be done in a number of ways - medium to advanced level "tricks", with none basic or very simple.

I keep all but one Firefox Profile on my D:/ hard drive with all my data, as you sound like you're doing. My "default" Profile stays in the default location on the C:/ drive so it works "as designed". All other Firefox Profiles are created [brandy new Profiles] or "placed" [moved or "cloned" Profiles] where I want them via a variety of "tricks". If that is what you want to do, just say so and someone here can help you with the "tricks".

See also:

• https://support.mozilla.com/kb/Custom+installation+of+Firefox+on+Windows

Did you try to create a new desktop shortcut via the right-click context menu in Windows Explorer?