Dragon Error: “COM returned an unexpected error code: Details are HOOKERR_NONOTIFYWINDOW”

June 14-2012:  See this blog post re the same error in relation to Adobe Flash & Web Browser issues.

Adobe Reader X (10.0.0) is the new bad boy on the block, and is wreaking havoc with Dragon NaturallySpeaking (Professional, Medical and Legal) users everywhere.  Whether you are using Internet Explorer, Mozilla Firefox, Microsoft Outlook, a web based EMR such as Med Access, and likely sundry other applications, you may receive the following error while using Dragon, specifically when turning on your microphone:  “COM returned an unexpected error code: Details are HOOKERR_NONOTIFYWINDOW”.  After receiving this error, you will be unable to use Dragon until you restart your PC.  However, shutting down all applications and restarting your PC will only temporarily resolve the issue, but it is not a fix.

The Remedy

  1. Verify your version of Adobe Reader.   Help> About Adobe Reader X.  Is it Adobe Reader X (10.0.0)?
  2. If 10.0.0., then try updating Adobe Reader to version 10.0.1, or the latest.  Help> Check for Updates.  As always, restart your PC after applying updates.
  3. If you already have Adobe Reader 10.0.1, or the above did not remedy the Dragon error message, you can try disabling Adobe Reader X’s Protected Mode (Edit > Preferences > General and deselecting Enable Protected Mode at startup).
  4. If the above fails to eliminate the Dragon error, completely remove Adobe Reader X (via the control panel), restart your PC, and install Adobe Reader 9.
  5. If the above does not provide a resolution to the Dragon error, remove Adobe Reader 9 via the control panel, and try another PDF reader such as Nuance’s free PDF reader.


  • If you have Adobe Acrobat Pro X, it is unlikely you will have this issue.
  • The issue may be intermittent and may occur in a multitude of applications, but not in others (i.e. the error may appear when using IE, but not MS Word).
  • This error may occur even if you do not have Adobe Reader installed — it’s entirely possible that any application that prevents Dragon from “hooking in” will produce this error.
  • If one of the above remedies seems to function in removing the hook error, you may find yourself faced with a new Dragon error:  “SendKeys cancelled“.  If that is the case, please proceed with the next step in the above list of remedies.
  • If one of the above remedies seems to cure the Dragon errors, and you find yourself faced with the inability to select or correct text in Internet Explorer or other applications where FTC (Full Text Control) is available, proceed with the next step in the above list of remedies.

Why is this Happening?

The issue is not Dragon’s fault (believe me, I’m the first to raise a hand when Dragon is the heart of a problem), even though Dragon is providing the error message (and ceasing to function).  Most applications on a computer hook into one another in some fashion.  When a hook cannot be established, an application can become unstable and error out.

Dragon, in particular, needs to hook into applications so that you may launch them by voice and also for Dragon to determine Full Text Control compatibility.  Therefore, when it cannot hook into an application and you turn the microphone on (at which point Dragon must be available to do your bidding), you may see this error.

The bottom line really is that Adobe Reader X is incompatible with Dragon (versions 10 and 11, and likely earlier versions as well), preventing Dragon from accessing certain applications.

Hopefully Adobe will provide their own fixes (they usually do), but if all else fails, remove Adobe’s PDF reader and install another reader.

This entry was posted in Speech Recognition, Dragon, Support Dragon & Mics. Bookmark the permalink.

37 Responses to Dragon Error: “COM returned an unexpected error code: Details are HOOKERR_NONOTIFYWINDOW”

  1. K-B-L says:

    I posted the original question. Thank you. Your solution to disable the protected mode worked. Adobe had updated to Reader X.

    I am dictating this in Mozilla. I started with Dragon in 1998, and often get frustrated with the incompatibility issues created through software up dates. I will check your website out next time I have another Dragon issue.

    • admin says:

      Glad it helped. The issue had been on our periphery for some time, but it seems, of late, it’s more pronounced (likely due to people upgrading to new PCs).

      And yes, please subscribe to our blog or check it on occasion. Cheers!

  2. Bernie says:

    Hi, thank you so much, I would never have been able to work this out myself. The Nuance website was of no help. Bernie

  3. Gyles says:

    I am getting the same error using Dragon Naturally speaking with Google Chrome.. If I have been using NS with Word and then click into a Google Chrome writing box – for me this is most commonly in Gmail, but it also happened with this box, I get the HOOKERR_NONOTIFYWINDOW error.

    • admin says:

      The good news is that this will likely be resolved in the update to version 11.5. If you use Medical, you will sadly have to wait a little longer.

  4. Risa says:

    THANK YOU for your efforts at helping!

  5. Tim Alvey says:

    Interesting & well written article. Any ideas how to fix the same error on GE Centricity 10 running via the Citrix PN Agent…

    • Alexandria says:

      Make sure that you have completely removed Adobe reader from the registry. Failing that, you may wish to contact Nuance directly. Good luck.

  6. Dwight Bryan says:

    I’m having this problem quite often, but I don’t have Adobe Reader, I use Foxit PDF Reader 5. I haven’t even installed Adobe reader on this new computer EVER… I remember a year ago I used to use it, and it always messed up Dragon, so I vowed never to use Adobe Reader again.

    So now that I’m not using it and it’s happening again, I have no idea what to do… any help? It would be greatly appreciated… I’m unable to use a keyboard because of a physical disability, so it’s very important that Dragon NaturallySpeaking always works. It is my main means of typing. I’m using Dragon NaturallySpeaking 10.1 Professional, I also have 11.5 Professional, but the same thing happens no matter what version I use. I have even uninstalled it a few times and reinstalled it. I even uninstalled the visual run time thing (I can’t remember exactly what it’s called) it comes with which is required to run Dragon NaturallySpeaking. I tried uninstalling 10.1, and then reinstalled it. Then I upgraded to 11.5. Then I uninstalled 11.5 and went back to 10.1.

  7. Pedro says:

    I have been having this problem a lot In Firefox. I can use Dragon again if I restart it and it works fine in Notepad.

    the problem started after I updated Adobe Reader but it persists even if I uninstall it (and I tried everything suggested above).

    any ideas on how to fix it? restarting Dragon every 10 min. is quite annoying…


  8. Pedro says:

    thanks for the quick response, Alexandria. This might indeed be the problem because I also updated my flash drivers.

    this morning I disabled flash in Firefox as you suggested and haven’t seen the error again.


  9. Manu says:

    je suis tétraplégique depuis un accident de moto survenue le 02/07/04 et j’avais ce problème depuis une semaine alors que je n’en avais vraiment pas besoin je vous remercie cela marche impeccablement je suis à nouveau un tétraplégique heureux bien amicalement Manu

  10. Dwight Bryan says:

    I just wanted to let you know… downgrading to the previous version of flash fixed the problem! Thank you so much for your help. Nuance could not fix it but you did in no time! I can’t thank you enough.

    • Alexandria says:

      You are most welcome, Dwight. As the issue is still “outstanding” in Nuance’s system, I think any sort of advice or workaround is not known to most of their support people.

      In truth, I have no idea what Nuance can do as it’s a tricky issue stemming from Adobe yet interacting with other PC aspects.

      At least there is a workaround!

  11. Hi Alexandria,

    Thanks a lot for the post! I had this problem for a few weeks, disabling Adobe Reader X’s Protected Mode worked perfectly without having to restart the computer. (Win7 x64; Adobe Reader 10.1.3).


  12. Excellent post! After updating Adobe Reader, NaturallySpeaking was rendered useless on my system. First, I disabled the Protected Mode. That solved many of the problems and allowed me to dictate in Microsoft Word again. However, I was still having trouble dictating with Mozilla Firefox, Microsoft IE, and Google Chrome. I found your post and follow the steps to remove Adobe Reader 10. Now, I am able to WRITE THIS using Dragon NaturallySpeaking and Mozilla Firefox (my favorite browser).

    I am in the process of installing the Dragon PDF reader. It seems that software will convert PDF documents to Microsoft work documents. That is a significant benefit, if it will do that!

    Thank you so much for the help!

  13. Michael Rowland says:

    Thanks for the initial information plus all the informative posts made by others who have had the same problem.
    Much appreciated!

  14. David H. says:

    Thanks for your suggestions. (Nuance has been hopeless/useless, as usual.) I’m no longer getting the HOOKERR or SendKey errors. I have uninstalled all Java and Adobe applications (disabling had no apparent effect), run the Advanced SystemCare 5 deep clean mode (free version) , and uninstalled Dragon NaturallySpeaking preferred 9.51 (including speech files) and reinstalled Dragon, but the full functionality of the program has not been restored. I’m using Firefox 13.0.1 and Vista SP2.

    Many commands still no longer have the desired effect: attempting to open a website using Firefox’s shortcuts toolbar (e.g., “click Netflix”) and other commands (e.g., “click next”) have no effect. “”Go forward”/”go back” and “go to top”/”go to bottom” seem to be the only ones that are functional.

    Any thoughts other than the ones you’ve already posted on how to return Dragon NaturallySpeaking with Firefox to its full functionality?

    Thanks for any help you can provide.


  15. Michiel says:

    This was a nasty problem but excellent help. Disabling the protected mode was the clue. Thanks!!!

  16. Mike says:

    I got rid of Adobe flash version 11.x and downloaded version 10.3 Adobe flash. Installed that, and it solve the problem. Thanks!

  17. TQC says:

    Thank you so much for this!
    Just had a new system upgrade (now on Win7-64bit) and all was good but this darndly and seriously frustrating error. Downgraded to 9.1 and its all humming along now.

    Thanks you guys!

  18. helen says:

    hey, i’ve uninstalled it, i’ve updated adobe and the problem is stil happening, i’ve had remtek online support trying to solve the problem, but sadly it is still happening. its making working very hard. i’ve got adobe reader XI, i have no idea what to do, think only opinion left is to unistall dragon and install it all over again, but then if the problem is with adobe then thats not really going to help.
    please if any one knows how to sort this, please help 🙂

    • Joe says:

      We’re also having the same issue.and with Adobe Reader XI. It seems this article was written before the new update. We haven’t uninstalled Adobe Reader and tried a re-install yet, but were you able to Helen? If so, did it work. Are you still getting the same error message? Or did you uninstall and re-install Dragon Medical?

      In the current Adobe Reader version XI, I can’t seem to find anywhere to deselect the option to “Enable Protected Mode at Startup.”

  19. Bill says:

    Just provided a 2015 update, saw this same issue and it was when a DR is working in EMR and using Dragon. The only time he was getting the HOOKERR error was when he would add and addendum or a flag update to a chart. The machine was 7 Pro x64 with Adobe XI. I was able to correct the issue by going into Adobe/Edit/Preferences/Security (enhanced) and under sandbox protections and unchecking Enable protected mode setup at startup. User rebooted machine and it corrected the issue.