Microsoft Outlook Error – “Cannot start Microsoft Office Outlook. Cannot open the Outlook window.”

When going to open my Outlook email client this morning I received the following error message:

“Cannot start Microsoft Office Outlook. Cannot open the Outlook  window.”

Cannot start Microsoft Office Outlook. Cannot open the Outlook  window

This was easily solved by running the following command from the ‘Run’ prompt. *IMPORTANT: Make sure that you have a space between the ‘Outlook.exe’ and the ‘/resetnavpane’ command switch.

“Cannot start Microsoft Office Outlook. Cannot open the Outlook  window

If you are running Windows Vista or Windows 7 you won’t have the ‘Run’ option enabled by default.

“Cannot start Microsoft Office Outlook. Cannot open the Outlook  window

To enable ‘Run’ option go to the ‘Customize Start Menu’ section and check the ‘Run command’ box.

“Cannot start Microsoft Office Outlook. Cannot open the Outlook  window

Everything going well this should fix you’re “Cannot start Microsoft Office Outlook. Cannot open the Outlook  window.” error.



  1. egrand says

    The Outlook.exe/resetnavpane won’t work on my Vista computer…it tells me that it cannot find that prompt

    anything else i can do?

    • Anwar says

      error message “cannot start microsoft office outlook. cannot open the outlook window”
      its working

  2. cicostas says

    THANK YOU SO MUCH! The spacing worked… I have been working on this for hours including deleteing registry and nothing worked. THANK YOU!!!

  3. Anne says

    Thank you this worked – with the space. Why does this suddenly happen though? Bit worrying. It followed a Windows update….

  4. Joe says

    Fantastic! i followed this and got the problem fixed in a second. This is after spending hours looking up other sites & microsoft help which was a complete waste of time. Thanks again.

  5. Erik says

    Major thanks, worked the first time! This happened for me when I was sycning folders over a VPN connection, outlook blew up, then blue screen of death as i was shutting down outlook. Thanks again!

  6. Paul says

    I had just got the error after my system had rebooted after Automatic Update which included some Outlook patches – thought I was going to have to reinstall or restore. Your fix has saved me a lot of time. Thanks.

  7. Beth Stenger says

    Thank you for the information regarding cannot open Outlook. I have been working on that problem all day and your solution solved it in seconds. Thank you!

  8. says

    Thanks so much! I was trying the “outlook.exe/resetnavpane” solution with no luck at all – UNTIL I saw your solution to add the space. It worked! I’m running Windows 7 .. don’t know if that’s why. All better now – thanks again!

  9. Kamran says

    Myrna: I tried that on Win7 and it worked.

    However, I observed that all my previously configured search foloders and favorites folders are gone. My configuration for “Mail” view has been resetted to initial as well (I had customized it as per my convenience).

    Although, these are minor issues as compared to the original one but I am really curious about what went wrong and what this command did to fix it.


  10. Graham Down says

    Many thanks – works perfectly. Should have tried your site first rather than going to Microsoft 1st and wasting several hours!!

  11. Bill Ando says

    Worked a treat many thanks.I did the same as Graham above. Should have know microsoft wouldn’t of know how to fix their own product.

  12. Mark says

    Great tip about the space between. Used alternate program for weeks before discovering this site. Thanks again.

  13. Jeff says

    OMG! It worked! Thank you so much.
    I’ve spent hours working thru microsofts useless support docs on this problem, all to no avail. Then I stumbled on your fix, and it fixed the problem in seconds.

  14. phonske says

    Worked a treat. Thanks for sharing. I tried almost everything including reinstalling and repairing Office suite was about to clear the registry after 4 days of on and off effort.
    Thanks a million people like you are stars in their own right. God bless.

  15. says

    Yes worked fine for me too but I have to do it everytime I reboot – is there a way to make it a permanent fix?
    Or is there something on my computer causing this to happen?
    Outlook had been working fine previously and I’d hadn’t made any changes or added any new programs it just suddenly started doing this for no apparent reason.
    Using new computer with windows 7

  16. says

    It worked for me too, but I did it yesterday and today had the same “crash’. The computer went blue screen to “protect data loss”, when I rebooted I got that message in office 2007. “Couldn’t open the windows screen..” I ran the code suggested and it’s now working again, but the question is why is it happening repeatedly?

  17. says

    just a follow up to my previous post where i had the problem that i had to do the fix everytime i started up (new dell computer, windows 7) – it actually stopped doing that after about 5/6 times and is now a permanent fix, no idea why as i changed nothing, but great anyway, thanks again!

  18. jim says

    Thank you so much. After looking around for fixes that seems complicated, this was amazingly elegant and simple. Best of all it worked immediately.

  19. Bart Grefte says

    Unfortunatly, this does not fix this problem over here.

    Both Outlook 2010 beta and RTM have this problem immediatly after a clean install (with clean I mean XP clean installed as well).

    Some things I noticed:
    – With /safe Outlook works normal;
    – /safe:1 not, same error;
    – /safe:2 the Dutch error roughly translated: invalid argument
    – /safe:3 Outlook works normal;
    – /safe:4 same as /safe:2

    When the error occurs, just before that Outlook shows that “ms office is being configured” window which only should show during 1st start, it does not show with /safe and /safe:3.

    Something I found with Google:
    1. Locate HKEY_CURRENT_USERSoftwareMicrosoftWindows NTCurrentVersionWindows Messaging Subsystem
    2. Delete the Profiles key under the Windows Messaging (Subsystem) key.
    ^ does not help.
    Not his also

    Any idea’s?

    • says

      Hi Bart,

      That isn’t a problem I’ve come across as yet. That said, I have yet to upgrade to Outlook 2010 as it is not currently compatible with the Blackberry Desktop Manager.

      Anyone else out there have any advice or ideas that may help Bart?



    • says

      Thanks to everyone who have taken the time to leave a comment – I’m so glad that this post has managed to help you. :)

      All the best,


  20. Bart Grefte says

    Kiwi Si, problem is solved :)

    Someone on the Dutch forum mentioned that Outlook 2010 is depending on Windows Desktop Search 4.0, that was not installed….

    Now for some reason Outlook did not mention this in the error and it should’ve start up normally without Desktop Search installed, but for some reason it did not.
    After installing Desktop Search 4.0 Outlook started up without problems.

    This might explain the problem:
    I’ve been using updatepacks from the RyanVM board to update my XP disc. I remember something about the maker of the (Dutch) post SP3 updatepack doing something with the Desktop Search update, although I don’t remember what. It didn’t seem installed and it did not appear at MS Update so there was something going on.
    Add to that that I just now installed Outlook 2010 on a clean XP install with only SP3 and nothing more installed, not the updates released after SP3 and not even Desktop Search 4.0.

    …. Now Oulook starts up right away, no error, but it does mention on the main window that Desktop Search is not available.

    Think I’m gonna have a talk with the maker of the updatepack :)

    • says

      Hi Bart,

      Apologies for the delay in replying and thanks for taking the time to let us know about the Desktop Search 4.0 fix for Outlook 2010. :)

      That will likely catch many new Outlook 2010 users out.



  21. Bridgette says

    This worked for me, thank you! Any ideas why this happens? It occurred on a new computer, and Outlook was only activated today. Outlook was working fine during the day, and the error occurred when restarting Outlook after the computer was idle for a while. Very frustrating, very thankful for your post!

  22. Richard says

    Just a little tip on errors like this. When in doubt, run process monitor from sysinternals. That will reveal the problem in many cases.

    • says

      Hi Richard,

      Good tip.. Totally agree – what a great util. I attended a session a Microsoft TechEd a few years ago where Mark Russinovich demonstrated how to troubleshoot with it – cool stuff! A must have addition to any self respecting admins tool box. :)



  23. Bart Grefte says

    Kiwi Si,

    I’ve found out more about what was going on.
    The maker of the updatepack added 2 registry keys that made Windows, Outlook and MS Update see Windows Desktop Search 4 as installed (while it was not), this to prevent WDS from showing up at MS Update.
    These are the keys in question:

    HKLM,”SOFTWAREMicrosoftWindows Search”,”CurrentVersion”,0x0,”04.00.6001.503″
    HKLM,”SOFTWAREMicrosoftWindows Search”,”SetupCompletedSuccessfully”,0x10001,01,00,00,00

    Just deleting those is enough to get Outlook working, although because of the absence of WDS some (search) functions will not work but the main functions of Outlook do.

    So problem solved 😀

  24. says

    Microsoft provide inboxrepair tool for damaged .pst file. If inbox repair tool can’t help you then use 3 part repair pst file software . you can find various 3rd party tools on Internet but one of the tools that I have come across can be found at – kernel outlook recovery software

  25. jw says

    Thanks for the fix. I cannot believe this error could occur without Microsoft issing a fix. It really p*sses me off–I tried Restoring, Reinstalling, Repairing, etc. and notnhing worked until I read your fix. Does anyone know what the heck causes this and why won’t repair work?

  26. Jordan says

    I have Vista and I get no error message, but Outlook 2010 simply doesn’t open after clicking on the icon. The little circle thingy spins around for a few seconds, as if preparing to open, but then it stops and nothing happens. I’m loathe to mess with registry keys because I’m not that geeky. Is there a way to get Outlook 2010 running?

  27. says

    Hi, can anyone help me out there. I am getting frustrated and my computer is about to go for a flying lesson.

    My 7 year daughter clicked yes to something the other day but couldnt remember what. Now when I try to open Microsoft Office Outlook I get the message “cannot start Microsoft Office Outlook. Cannot open the Outlook window”.

    I saw your response and have tried the above ie. the resetnavpane etc. but now I get a message saying “Cannot start Microsoft Office Outlook. The command line argument is not valid. Verify the switch you are using”.

    Does anyone know what this means and how I fix it.

    From a really frustrated self-employed secretary who needs her emails. I can access them via another source but its not great. Forgot to mention I am on Windows 7 ultimate.

  28. TweeZz says

    I had the same error when trying to open a *.eml file.
    I have 2 mail apps on my computer. Thunderbird and Outlook. When Thunderbird is set as the default app to open eml files, I get the error.
    After setting Outlook as the default app to open eml files, it works just fine.

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