Hello i had the issue with "device not found" and couldn't find any solution that fixed it for me.
Anyhow when i installed trackir software/drivers on main computer (probably reinstalled it 5 times at least) that i already installed on before it only installed
"C:\Program Files (x86)\NaturalPoint\TrackIR5" so going to device manager to update drivers didn't work.
Now i went to my laptop that i never installed that software on before, it installed 2 folders
"C:\Program Files (x86)\NaturalPoint\TrackIR5"
"C:\Program Files (x86)\NaturalPoint\USB Drivers x64" <-- what you need
Get USB stick into the other computer and copy USB Drivers x64 to it.
After that plug it back at computer that didn't work and put in same folder. Now it should work to go to device manager and update driver from that folder.
Whats weird is that it seems if you installed the software on a computer before it doesn't install that driver folder again.