Outlook 2010 error “Cannot open your default email folders. The information store could not be opened”

Today I couldn’t start my Outlook 2010 client anymore. When launching Outlook, the following error message came up:

Cannot open your default email folders. The information store could not be opened.

I always start with some basic steps, that helped me most of the times when I had a problem with an Outlook profile. Those standard steps are listed at the bottom of this article. However, the problem involved with this information store thing could not be solved with my standard steps.

To solve the “Information store could not be opened” –error, I disabled the Compatibility mode on Outlook.exe (who actually did turn this on?! It just suddenly was enabled!)

To disable the Compatibility mode on the Outlook.exe application, do the following:

  1. Open Windows Explorer and navigate to your Office directory (default is “C:\Program Files\Microsoft Office\Office14” for Office 2010, but your Office may also be installed in Program Files (x86) )
  2. Right click the Outlook.exe and choose Properties
  3. Click the Compatibility tab and UNCHECK the “Run this program in compatibility mode for” option
  4. Click OK and try to launch Outlook again

If the Compatibility mode was not enabled, then your problem is caused by something else :)

Try my default steps to see if it solves your particular problem:

  • Try to Run outlook in safe mode from the Run As window. To do so, press WIN+R (Windows key+R), type “Outlook.exe /safe“ in the text field and click OK.
  • Recreate your outlook profile. To do so, click Start –> Control Panel –> Mail. Click Show Profiles. Remove your existing profile. Then click Add… to add a new profile. Try to start Outlook again.
  • Remove the Windows Messaging Subsystem keys in your registry. To do so, press WIN+R (Windows key+R), type “regedit“ in the text field and click OK. Navigate to [HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles]. Delete the key that corresponds to the profile name that causes Outlook not to start. Try to start Outlook again.

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47 Responses

  1. Waseem says:

    Really nice problem solved

  2. anand says:

    you can go to control panel and configure manually ,its stars working ,problem get solved

  3. Allen Martin says:

    I finally found a website with a solution that works. Thank you so much.

  4. Sheen Soloman says:

    thanks a lot for help.. thanks…

  5. Monster says:

    It worked like a bomb

  6. ZJ says:

    To whoever you are,

    I have struggled for DAYS with this problem and was only till I found this page and tried one of your last options that I found a solution deleting my profile and starting again!


    Great work

  7. Carlos says:

    Thank you for the great effort.
    Unfortunately it didn’t work for me. Could not open Outlook 2010 on safe mode.
    The error message I get is:
    “Cannot open your default email folders. The file C:/………pst cannot be opened”
    Boo-hoo, I am desperate!

  8. alan says:

    YAY !!! was in safe mode – spent many hours to correct – you rock !!!! Thank you and blessed Easter

  9. Anonymous says:

    Thank you for the post, without your wonderful instruction I might not be able to get my Outlook 2010 to work. Thanks !!!!

  10. Naveen says:

    Thank you for the help…its resolved now

  11. Tonin says:

    Nice one. Just like Marla I had been going around this issue for hours, many forums and m$ useless kb’s. In the end it was the compatibility issue. Thanks

  12. I have tried to fix this issue for over 3 hours until I ran across this post. This worked!! Thank you so much.

  13. Sheryl Ryan says:

    YOU ARE A GENIUS! been trying to get this error fixed for the last 2 days – you are the only one that suggested disabling “compatability”.

    Thank you!

  14. raghav says:

    1st I would like to Thank u for the support.
    I have spent 2 hours for this soln finally I got it on this blog.
    Really its very useful

  15. Santosh says:

    i m so much happy i got the solution of this problem..
    thanks a lot..

  16. sandeep chander says:

    thank you. it worked!!!!

  17. Luvsaa says:

    Thank you very much. It was very helpful!!!

  18. trainor says:

    Thank you very much. This solution took 5 minutes to solve a problem that Microsofy Exchange Support took 5 days to further mess up

  19. sudheer says:


    This is quite nice investigation on the ways to resolve the problem.Thank you my problem resolved.I really appreciate the given solution.


  20. Ted lee says:

    Thank You! Thank You!

  21. reg morris says:

    ON anaother computer I had divided my .pst file into smaller files due to reaching a size limit (of around 4G). But this computer refused to open the new .pstfiles and gave the message; “Information store could not be opened”.

    I tried reparing, changing permissions, etc. All to no avail.

    Then along came this brilliant solution!!!!!

    I now now ‘how’, but not ‘why’. You would have though compatibility mode would enable MORe files to be opened, not less.

  22. riya says:

    omg thank you sooooooooooooo much ! I’ve been trying to find a solution for months now. I’m so happy!

  23. Larry Autman says:

    Used this from your suggestions…
    ◾Recreate your outlook profile. To do so, click Start –> Control Panel –> Mail. Click Show Profiles. Remove your existing profile. Then click Add… to add a new profile. Try to start Outlook again.

    On Windows 8 with outlook2010 I had to use the AD domain login rather than my email address which is also a Live ID. When it asked for my password and my email address was the account it failed. However I used the “Use another account” and supplied my domain\username password.

  24. Oksana says:

    Thank you!!!!

  25. ahmad faez says:

    many thanks…it’s really helpfull…

  26. ladycdw says:

    Thanks sooooo much! This had been driving me crazy for a week!

  27. BOFHse says:

    Compatibility mode! AAARGH! Thanks! :-)

  28. jams says:

    2 cents… I uninstalled COMODO internet security and the problem went away.

  29. Lan says:

    No solucioné nada.

  30. Abolfazl says:

    Thanks a lot

  31. Boggy says:

    Excellent.. Unchecking the compatability mode worked for me also.. Nicely found.



  32. Tony says:

    after several rounds including removing office and starting over… this post put me over the edge… thanks for the help.

  33. Vince caruso says:

    Thanks so damn much! Unchecking worked like a charm…..I love this thing they call internet.


  34. Robert says:

    Thank you! Removing the old profile did it for me!

  35. Mathias says:

    Deleting the registry key worked for me. Thank you!

  36. Ole says:

    Awesome. Thanks.

    Spent over an hour deleting, recreating, trying different accounts, while a stupid compatibility setting was to blame.

  37. Spazz says:

    For me it was the removing of the registry key that worked. Thanks.

  38. Str8b8r says:

    Awesome!..excellent solution!

  39. Stumpus says:

    Thanks for this. I have no idea why the compatibility mode was enabled.

  40. E Jiin says:

    I could have spent hours looking for that Registry Key!!!!

  41. Mike says:

    Wow……it’s always the simple things.

    Spent ages trying all different Outlook switches to get it to work….NADA.

    Turn of Compatibility Mode and voilà! Works

    You’re a lifesaver….thanks a million!

  42. Sanjay says:

    Thanks a ton….i have been looking for the correct solutions on internet, you tube for months but nothing worked.

    Your above solution to remove the entry from regedit worked for me.

  43. Lizi says:

    Thanks a heap!!
    We’ve been investigating this issue for hours. this solution worked.

  44. Sivasankar V says:

    Thanks this helped a lot… when my exchange configuration was not correct i accedentally set the compatability mode to on…

    thanks again.

  45. Jim Phelps says:


    I’ve spent hours trying to figure out why OUTLOOK would not open.


  46. vishant says:

    solution provide by u, its work no need to apply any other setting.
    Thanks for your help.
    TC by!!!

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