Logitech Unfying USB Key No Longer Recognized

TairikuOkami said:

Check, if you have all the drivers.

Driver Easy Free Driver Updater

Also note, that firmware has to be updated manually, maybe it is blocked due to security reasons by something?

Logitech Response to Unifying Receiver Research Fi... - Logitech Forums

None of the displayed drivers in that program relate to Logitech.
I cannot do what the second link suggests because as previously stated:

ChickenShark said:

YES, I HAVE installed SetPoint and Unifying Software from the Logitech support page multiple times, neither recognize the device as plugged in.

I will look into the drivers that the program says are outdated to see if there's a fix in there. Thank you for your suggestion.

I believe it is by default, at least I have not touched settings for it. I will see to that, thanks.
I did not know that it was disabled, thank you for noticing that.

Edit:
I cannot believe myself. Apparently that was the issue.
I have no idea how that became disabled, I suppose somewhere along the update. Again, thank you very much for noticing that.