Musings of a PC

Thoughts about Windows, TV and technology in general

Does your Outlook window stay on top of all other open windows?

Since upgrading to Office 2010, I’ve occasionally found that the main Outlook window stays on top of the window stack. This means that if you click on a URL or reply to an email, those windows actually open behind the Outlook window so you can end up thinking that nothing has happened in response to your actions.

When this first happened to me, I did some research and found a thread that suggested fixing some registry keys. I checked the values on my installation and found suitably “wrong” values but wasn’t entirely happy about changing them because the thread didn’t really explain how those values could be wrong and what the different values meant. Since the specific registry keys were related to Outlook add-ins that I had just installed, the social connector options, I just uninstalled them and the correct behaviour was restored.

However, Outlook has just reverted to bad form, staying on top. A quick Bing and I found the thread again so I thought I’d blog about it this time so that I’ve got the corrective action and the original thread.

Registry keys for Outlook add-ins are located in HKey_Current_User\Software\Microsoft\Office\Outlook\Addins. Each add-in has a DWORD called LoadBehavior. According to this thread, if the value is set to 3 instead of 2, this will cause Outlook’s main window to be at the top of the Z stack when the window is open, preventing any other window opening in front of it.

The corrective action is to change those values back to 2 and restart Outlook. What I am struggling to find is an explanation of what these values mean. This article, for example, actually suggests that 3 is the correct value and that setting it to 2 actually disables the add-in! In which case, all I’ve ended up doing is disabling two add-ins in my copy of Outlook and, for some really bizarre reason, one of them seems to be causing the Outlook window to stay on top!?!?! Doesn’t sound like an entirely satisfactory solution to me!!!

60 responses to “Does your Outlook window stay on top of all other open windows?

  1. Glenn May 6, 2011 at 7:58 am

    Hi Philip!

    Thanks a lot for your blog entry. I had the same problem and your answer solved the problem. I have 4 addin entries: AccessAddin.DC, ColleagueImport.ColleagueImportAddin, iTunesAddIn.CalendarHelper, and UmOutlookAddin.FormRegionAddin. Only the first one had LoadBehaviour “2” as a value. Changing it to “3” and restarting Outlook brought everything back to normal. Thanks a lot again 🙂

  2. Daveonator May 27, 2011 at 1:32 pm

    Thank you, for some reason an Access add-on was messing me up it (2 instead of 3). I’ll bookmark this page.

  3. chris July 25, 2011 at 3:29 pm

    Hi Philip – This is exactly the problem I’m having but I’m not sure how to make the change you’ve suggested. Please help me understand how to access where these add ins are located so i can change them.

    • Philip Colmer July 25, 2011 at 4:52 pm


      I’ve edited the post slightly to make the registry path clearer. You need to be familiar and comfortable with using RegEdit to make the changes required. Hopefully, if you are, the clarification in the post should make it easier for you to find the appropriate registry settings.


      • Keith April 19, 2012 at 8:54 pm

        Philip – you rock! This has been driving me nuts for months, and all is solved. Give yourself a big raise and take a week off!

      • Keith May 1, 2012 at 4:21 pm

        So the plot thickens…after my success on April 19 (below), the pesky problem returned a week later. All three of my LoadBehaviours were at 2. I changed them to 3 and restarted Outlook…no luck. Went back into regedit and changed them all back to 2, restarted Outlook and life is good again. Can’t think of what happened between April 19 and the recurrence. BTW – the “unlock/lock” issue with the task bar had no affect on my instance.

  4. stevehuston July 28, 2011 at 9:01 pm

    I tried this too and had haphazard results. After more web searching for answers, the technique that apppears to work for me (at least for a few minutes now 😉 is to right-click on the taskbar, unlock it, then lock it again.

    No, I’m not kidding 🙂

  5. Sue Bishop September 19, 2011 at 8:52 pm

    OMG, I just tried stevehuston’s solution and it worked. This is crazy… Thanks though!

  6. Ed October 6, 2011 at 8:39 pm

    Just shut outlook down and back up again. Worked for me.

  7. Steve October 11, 2011 at 8:39 pm

    Thank you so much. This was driving me nuts and your solution worked great

  8. Chad October 12, 2011 at 4:06 pm

    I did the lock unlock taskbar and that solved the window stacking issue, but I am still getting items stuckin my outbox since I installed the CRM Outlook plugin.

  9. Tom October 17, 2011 at 5:49 am

    MSDN told me following:
    When you register your add-in under one of these registry keys, the information written to the key includes the following name/value pairs: Description, FriendlyName, and LoadBehavior. Description is a string type that provides a short description of the COM add-in. FriendlyName is a string that contains the name displayed in the COM Add-Ins dialog box. LoadBehavior is of type DWORD, where the value is an integer that specifies how to load your COM add-in. This integer can have a value of 0 for Disconnected, 1 for Connected, 2 for load on startup, 8 for load on demand, or 16 for connect first time. You can combine these values to create different types of load sequences. For example, if you assign the value 3 to LoadBehavior, the add-in will be loaded on startup as well as connected. If you assign 9 to the add-in, the add-in will be connected and demand-loaded when necessary, such as when the user clicks a button that uses code in the add-in.

    So if you are still having issues, try 0 or 16…

  10. Lee November 28, 2011 at 5:04 pm

    I tried Stevehuston’s suggestion several times and it did not work. Instead I had to right click on the task bar, click properties, uncheck “lock the taskbar”, click apply, then go back through properties and check “lock the taskbar” and then “apply”. For some reason this seemed to work…..(for right now).

  11. Mike December 30, 2011 at 4:16 pm

    Thanks for your post. iTunesAddIn.CalendarHelper was my culprit. FYI:I found link to LoadBehavior on another site (

  12. oded January 10, 2012 at 12:05 pm

    changine 2 add-ins to “2” worked just fine and solved the problem. Salesforce for outlook and a google app.

  13. Ben February 1, 2012 at 6:27 pm

    Worked like a charm, thanks alot….man that was frustrating!

  14. Karl Monger March 6, 2012 at 3:26 pm

    Thanks – had this issue, googled and found your answer. Worked perfectly.

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  16. Shannon April 12, 2012 at 4:16 pm

    Thanks a ton- this was driving me crazy as sometimes Outlook stayed on top, and other times not. Changed ColleagueImportAddin from 3 to 2. Great reply from Tom as well.

  17. Francis - Investing Epimoni April 25, 2012 at 9:06 pm

    Well I found a DWORD LoadBehavior of 9 on “Microsoft VBA for Outlook Addin” Based on toms information it is connected and loaded on demand. Also I get the sound asking for a confirmation to run as admin, but no visual window.

  18. Francis - Investing Epimoni April 25, 2012 at 9:07 pm

    Changed everything to 2 and it seems to have worked after toggling the lock on and of leaving it off worked as well. Thank you for all your help.

  19. Roy May 8, 2012 at 1:41 pm

    Disabling the Salesforce for Outlook 2010 add-in did it for me. Go through File / Options / Add-Ins, “Go…” button and uncheck the box next to the add-in(s) you want to disable — no need to mess with the registry if you’re simply disabling/re-enabling the add-in. I was able to re-enable the Salesforce add-in and the problem is still “fixed” — would like to get at root cause though.

  20. Maen June 10, 2012 at 7:35 am

    Brilliant! Solved my problem in less than 1 minute!! it was because of the add-on thing.

    Thanks a lot mate!!!!!!!!

  21. Anatoly August 16, 2012 at 9:05 am

    Thanks a REALLY REALLY LOT!!! 🙂

  22. Helen October 9, 2012 at 9:35 am

    You guys rock! Only just started doing it today and was already starting to annoy me! quick google search and found this blog! Fixed! Thank you!

  23. Mark R November 8, 2012 at 11:15 pm

    Didn’t work for me.. Tried both option, no joy..

  24. David November 9, 2012 at 4:08 pm

    This fixed things up for me… that a lot for the information. This issue was so annoying!

  25. raleighgirl73 November 15, 2012 at 3:04 pm

    Bless you stevehuston. Google and stevehuston ROCK

  26. wakingsky November 27, 2012 at 2:26 pm

    Ugh! this was so frustrating. thanks for the help. I had to “lock” the taskbar, close out of outlook and then when I reopened outlook, it worked. WEIRD…

  27. WindowsOutlook December 7, 2012 at 1:44 pm

    I have found a simple soultion: hold down the “Windows” button on your keyboard and tick the right arrow button once or twice. Problem solved (for me at least)

  28. ThisIsWhyIUseMac December 13, 2012 at 5:04 pm

    These solutions (taskbar unlock/lock and fiddling with the Add-in load values in regedit) work temporarily, but the problem returns each time I log out and log back in again. I need my add-ins to perform my job, so they can’t be disabled.

    Does anyone have a PERMANENT solution?

  29. Peter B. Steiger March 4, 2013 at 3:07 pm

    Another grateful reader here. My “stay-on-top” behavior started after I added a secondary mailbox to my login account, and sure enough the “colleague.import” addin had a load behavior set to 3. Change it to 2, and all is well again. Thank you, thank you, thank you!

  30. Kuun April 8, 2013 at 11:19 am

    Thanks, it worked for me as well.

  31. Bert Rievers May 2, 2013 at 7:26 am

    Hello there! Of course I also encountered the described problem, changed the registry settings for the load behaviour and outlook was not “boss” anymore. I have a remark/tip for you all though, especially for Philip Colmer: the Z Stack could very well have the same meaning as the Z-index in HTML nowadays (I don’t know since which version). Anyway, I had the same kind of problem with a menu in a website generatede by the program “Artisteer” once. When the website was published and a photo gallery opened, the menu bar was consistently placed OVER the photo gallery. After some searching I found the CSS setting z-index, whitch was set to 10000. I changed that to 1 and my problem was solved: The gallery popped up over the site and was not disturbed by the menu bar anymore. So changing the load behaviour may very well not disable the add-ins, but only determine their load behaviour in respect to the display order.

  32. mntyfrsh May 2, 2013 at 5:25 pm

    This is a ridiculously strange workaround.

    Open Outlook, click File -> Options. Click OK to close the Options window. Now open a message and notice it opens ON TOP of the main Outlook window.

    This must be repeated EVERY TIME Outlook is opened.

    Salesforce – seriously, hire someone who can code a proper plugin – pleading ignorance on your site to this obvious and known issue is pathetic.


    • KathyJ May 3, 2013 at 7:56 pm

      I am a Salesforce user. I had no idea until I read your reply that it had anything to do with the Salesforce plugin. This has happened a number of times, most recently today. I decided that I was going to try to find out why, before I did any more work. Glad I found this site. Thanks so much,

      • Pded May 4, 2013 at 1:32 pm

        The load behaviour is being changed to 3 or 8 by these applications and every week I need to change the registry back to 2:

  33. Ismaiel June 24, 2013 at 3:29 pm

    Superb. Really helped me in solving this outlook issue that is hindering me for the whole day today. Thanks a lot Philip Colmer.

  34. Mike Cone August 9, 2013 at 4:49 pm

    The key “LoadBehavior” was not present in my Addins path – so I added it as a DWORD and set it to “2”. Problem solved. Thank you!

  35. George November 1, 2013 at 7:42 pm

    I have an issue with a new install of MS Office 2010. Clicking on Outlook Causes Word window to open in compatibility mode behind Outlook and it will not go away. This is a little of topic, but can you help please? I have uninstalled and re-installed it and did the root change from 3 to 2 and still nothing.

  36. David April 7, 2015 at 4:03 pm

    I’ve changed ‘loadbehavior’ to several values, trying ‘2’ and “0”, changing ‘lock all task bars’ from locked to unlocked and back again. My Outlook 2013 continues to have zOrder as top most for email and in do so, prohibits accessing: 1) Create new mail 2) reply 3) reply all 4) maximize mail item (right click,maximize).

    the correct / normal zOrder is maintained for Calendar, Task List and people, providing access to all sub-items.

    An interesting behavior change. My outlook 2013 behavior began as REMINDERS unable to change/bring to front to dismiss. For reason I can’t explain, reminders began to work as designed and now mail took on the behavior of having sub-items in the background (higher z-order) then the primary outlook screen.

    • David April 8, 2015 at 5:29 pm

      I’ve pulled EVERY add-in (some via REMOVE on the add-in panel of OPTIOnS, some via OFFICE ADD/REMOVE from the Control Panel Programs and Features. With no (zero, zip, nada) add-ins present, Outlook remains on top and blocks access to 1) create new mail 2) reply 3) reply all and 4 ) maximize mail item.

      The only way I can send an email is shut down and open in outlook.exe /safe.
      Interesting is: SAFE:1 and SAFE:3 produce the same undesirable results as non-safe.

      • David April 8, 2015 at 7:53 pm

        Problem identified. Along the lines of removing EVERY add-in, I began with Task Mrg and starting killing ‘things’ that MIGHT be related to my Outlook prob. Low and behold, terminating a docking station display app, “DisplayLink” caused the screen to go blank, the ‘normal’ sound heard when the laptop is inserted into or removed from the docking station, and then approx. 7 second later the screen springs to life and my email that I was attempting write is present at the forefront.

        How the display software of the Display Link beyond HD doc station is the root cause of this issue and why the issue manifested more than 1 year after start of use of the docking station, will remain a mystery.

        Thank for your patience and your posts as they did help me narrow down and eventually find my root cause.

  37. kevin freels March 24, 2016 at 3:49 pm

    I don’t know about you all, but I think this is absurd. I’m on Office 2013 and STILL having the problem. In my case I had five different addins to switch to (2).
    But that didn’t fix it. So on a whim I followed the same path in HKEY_Local_Machine and found two more.
    This is an ongoing problem that exists through multiple versions and acts differently for different people. I have not installed the salesforce addin but I did install the evernote plugin and Sync2 to keep mu google and outlook calendars and contacts in sync. But they worked just fine for months and then out of nowhere just decided to change these values? It makes no sense. I’d like to install Office 2016 and see if I get the same thing but when I went to install I got a warning that something I use will break. Can’t remember what it was. So I’ve been waiting for a fix on that. I think I’ll install it on my desktop and see if I get the same issues. Has anyone reported this to MS?

  38. Appsite July 25, 2020 at 1:48 pm

    Unlocking the taskbar worked for me! Thanks stevehuston!

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