Home | Blog | Software | Reviews and Features | Forum | Help | Donate | About us

avatar image

Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
  • October 26, 2016, 10:04:41 PM
  • Proudly celebrating 10 years online.
  • Donate now to become a lifetime supporting member of the site and get a non-expiring license key for all of our programs.
  • donate

Author Topic: Logitech Unifying software permanently alters mouse firmware? How to revert it?  (Read 567 times)


  • Supporting Member
  • Joined in 2008
  • **
  • Posts: 6,073
  • Slartibartfarst
    • View Profile
    • Donate to Member
I wondered whether any DCF denizens could help to unravel a problem with this unifying process.
Using Win10 the other day, I experimentally took 3 meeces (Logitech M185, M215, M515).
They all worked fine, separately, using their 3 separate, individual/unique dongles. They used the USB device "Logitech HID-compliant cordless mouse".
As M515 was a Unifying dongle, I downloaded the Unifying software from Logitech support.
Then I installed it and, using the unifying software, paired the 3 meece to the M515 dongle. It worked a treat. Very impressive. The UI can display a report of the battery status (if the software can fetch the battery status) and the firmware version of each mouse paired.
Then I unpaired them all. That seemed to work fine too, according to the UI report.
However, when I then tried to use M185 with its own dongle, it simply would not work. Same for M215 and M515.
So I re-installed the unifying software. Made no difference.
I then re-pared the meece (using the Unifying software) to the M515 dongle. It worked a treat, as before.
So, the unification seems to aggregate mice or other devices when it pairs, without discrimination, and it seems that the firmware within each mouse is changed on pairing, so THAT mouse can ONLY work through the unifying dongle, and henceforth THAT mouse cannot work through its original dongle as a "Logitech HID-compliant cordless mouse".

So, it seems that I may have just disabled 3 mice (or 2 at least), in testing out the Logitech pairing functionality.

What I would like to know is, if the mouse firmware has indeed been changed (as would seem to be the case, by deduction), then how can one revert/restore that firmware to its default initial state? Leaving the batteries out of the mouse for a while doesn't seem to do it.
I haven't been able to find any info on this so far, which is why I posted this curiosity here.


  • Member
  • Joined in 2006
  • **
  • Posts: 2,084
    • View Profile
    • Donate to Member
From the description of your problem I get the impression that the unifying software disables the other dongle devices. It isn't that Windows doesn't recognizes these dongles, but that these aren't allowed to communicate anymore.

That would be easier to implement in the unifying software. Easier than changing firmware I would assume.

Best way to test this is to use the appropriate mouse/dongle combo on a computer where that unifying software hasn't been installed on. Chances are that it will work just like you expect it to. Which then lies the blame at the unifying software, not the hardware.

It would be the first thing I would try. Personally, I love every piece of Logitech hardware I (have) own(ed). But Logitech software? I would look for alternatives if possible...and if there wasn't, I would go without and use the device in its most basic feature set. The headache induced by their software cancels out all the enjoyment I get from using their hardware. 


  • Supporting Member
  • Joined in 2006
  • **
  • Posts: 2,768
    • View Profile
    • Donate to Member
According to this forumpost (tom's hardware) these cordless mice can only be paired to 1 receiver at any time. Usually the non-unifying receivers have a teensie weensie small pairing button available, that should start the pairing-process with a free-floating mouse (afaik, all these mice also have a pairing button, sometimes hidden in the battery compartment).


  • Charter Honorary Member
  • Joined in 2005
  • ***
  • Posts: 9,027
  • [Well, THAT escalated quickly!]
    • View Profile
    • f0dder's place
    • Read more about this member.
    • Donate to Member
Pairing button might not be enough - a colleague once borrowed the keyboard I had at the time, and I ended up having to ask another colleague to install the logitech drivers and re-pair the keyboard to my dongle, because I refused to install the drivers myself.
- carpe noctem


  • Supporting Member
  • Joined in 2008
  • **
  • Posts: 6,073
  • Slartibartfarst
    • View Profile
    • Donate to Member
@Shades, @Ath, and #f0dder: Many thanks for your helpful comments.
This note for posterity and other seekers.

  • It seems that once a Logitech mouse has been paired with a unifying dongle, then that mouse will only talk to that dongle, and will not then talk to its specific "original" dongle. That would presumably be due to a modification in the mouse firmware.

  • You can test this after the pairing (and I had already established this), by putting the specific "original" dongle into another computer, and the mouse for that dongle will still be unable to talk to that dongle, whereas, if you put the unifying dongle into that same computer, the mouse/mice that was/were paired to it will still be able to talk to it. So the pairing process is definitely to a sole, specific dongle (the unifying dongle, in this case).

  • I felt sure that there would be software available to modify these settings, but the unifying software only offered a feature to either pair or unpair a device/mouse to a unifying dongle. Unpairing a mouse did not enable that mouse to talk to its specific "original" dongle, and it effectively left one with an orphaned and otherwise useless mouse. I felt sure that would not have been a desirable design objective.

  • Of the 3 mice I had, the M515 was apparently the only one whose specific "original" dongle was also a unifying dongle. The purpose of the unifying dongle seems to be simplifying and efficient, making optimum use of a limited number of USB ports: instead of having to have a separate dongle for several Logitech devices (e.g., a mouse and a keyboard) that you might want to connect to a PC, the unifying dongle enabled a 1--> many communications channel for a single USB port. Thus, you would only need one dongle for "n" devices - (say) 2 devices (a mouse and a keyboard) - to communicate simultaneously through a single USB port. This is where "n" will probably have an upper limit, but it is at least 3, as I had already established that 3 mice could work simultaneously through a single unifying dongle.

  • I recalled that whilst I had been browsing the Logitech support site I had seen some downloadable software called "Options" for the M185 mouse, that I did not recall seeing on the corresponding web pages for the M215 or M515. I had downloaded and briefly looked at this, but it was not the  software to manage a unifying dongle and so I had discarded it. Fortunately, I had been taking lots of notes as I went and so I turned to my OneNote Notebooks and located my notes on the M185 mouse and used the support pages link to get back to the software download page for that mouse. There it was: the file Options_3.40.25.exe from the M185 downloads page http://support.logit..._us/software/options.

  • I installed Options_3.40.25.exe (this is on Win10-64 PRO), and it executed from the Start menu as "Logitech Options". After some experimentation, I found that this software seems to do just one thing - it enables the user to pair an orphaned mouse with its specific "original" dongle. I did this for the M185.
    The software only seemed to work for restoring a dongle+mouse combination that were originally supposed to be paired/matched, and where the mouse was currently orphaned, so once the pairing was restored, you couldn't repeat the pairing on that mouse unless it was subsequently orphaned from its own dongle again, nor could you pair an orphaned mouse with any other dongle except its specific "original" dongle (not even the unifying one), using this software. So it was very specifically a "one job only" kind of tool.
    So this Logitech Options proggie was exactly what I had needed.
    The M515 does not require such a tool (the unifying software fits that purpose), so I did not bother to test Logitech Options out on that particular mouse+dongle combination.

Meanwhile, I had placed a Logitech support website query which essentially stated the problem as per the opening post. When they eventually responded, it was to show that they did not seem to understand the problem, so I just sent them a reply that I had managed to fix it.

So, for the mice (but I assume it'd probably be the same for other Logitech devices that can work through a unifying port), it seems that they can only talk to a single dongle at a time and to which they have been paired (or are already paired by default).
By trial-and-error, I was able to figure out how to fix the problem I had stated.
The firmware in the two mice (M185 and M215) - once they have been paired to a unifying dongle or "orphaned" - can be reverted to ensure that they each only respond to their own specific dongles, by using the downloaded file Options_3.40.25.exe  from the M185 downloads page http://support.logit..._us/software/options
That is, running the executable Options_3.40.25.exe enables the user to reset each of the two mice to communicate only through their own specific dongles again.

Phew! - and respect for the Logitech engineers, though they could have published something more helpful about the need for and location of the Logitech Options software...(mutter, mutter)...

(By the way, I had earlier read about hidden reset switches on Logitech mice and so, before embarking on my voyage of discovery,  I closely examined each of the 3 mice in question, hoping to find some kind of concealed or tiny reset switch/button, but none of them seemed to have this, so - though I could be wrong, of course - I presume it might be a feature on some different types of Logitech mice.)
« Last Edit: July 21, 2016, 05:18:40 AM by IainB, Reason: corrections for clarity. »