Cannot start Microsoft Outlook, Cannot open the Outlook window

Today morning when I tried launching Microsoft Office 2010, I was greeted by this message – Cannot start Microsoft Outlook. Cannot open the Outlook window. It was a bit of an issue as I am a heavy user of Outlook for checking all my mails. In this post, I will show how you can resolve this problem.

Cannot start Microsoft Outlook, Cannot open the Outlook window

Looking around, I found a solution that worked for me. Here I am listing a few more in case my solution doesn’t work for you.

  1. Reset the Outlook navigation pane
  2. Repair Outlook PST file
  3. Repair Office using Online or Offline Repair options
  4. Fix Broken Outlook Profile

Make sure to use it according to your Outlook or Office version.

1] Reset the Outlook navigation pane

  • Open Run prompt using Win + R and type Outlook.exe /resetnavpane. Hit the Enter key.
  • The command will reset the profile settings, clear and regenerate navigation pane for the default Outlook profile.

2] Repair Outlook personal folder file (.pst)

Repair Outlook PST file

You can use the Inbox Repair tool (Scanpst.exe), which is designed to help repair problems that are associated with a personal folder (.pst) files.  There are two repair tools available:

The tool may run multiple times to repair the PST file completely. In some cases, if the PST file is beyond repair, and it recovers partially, then they are placed into the Lost and Found folder. The folder contains folders and items that the Inbox Repair Tool recovered. Unfortunately, things that are missing from the Lost and Found folder may be beyond repair

3] Repair Office

Microsoft Repair Office

If you have the original setup of Microsoft office, you can repair it. Launch the software, and it will offer you an option to repair all products of Office. Here is how you can manually fix office

  1. Right-click the Start button, and click on Apps and Features
  2. Select the Microsoft Office from the list, and then click on  Modify.
  3. Depending on what type of Office is installed on the computer, you will have two options.
    1. Click-to-run: It will open a window which will prompt—How would you like to repair your Office Programs. Select Online Repair > Repair or Quick Repair
    2. MSI-based: It will offer you to Change your installation. Here you can select Repair and then click Continue.
  4. Follow the instructions on the screen to complete the repair

An alternate way is to download the Office Repair tool. It can fix the problem with Outlook or can help you completely uninstall the product from the computer.

Related: How to Fix Office Outlook default Mail client Error

4] Fix Borken Outlook profile

Outlook 2010, 2013, 2016

  1. Click on File > Account Settings > Account Settings.
  2. On the Email tab, choose your account (profile), and then select Repair.
  3. Follow the prompts in the wizard, and when you’re done, restart Outlook.

Note: The Repair option isn’t available if you’re using Outlook 2016 to connect to an Exchange account.

Office 365

Fix Outlook Office 365

When using Office 365 and Outlook, you can download and install the Microsoft Support and Recovery Assistant from here. When you run this tool, it will prompt you for username and password to repair Outlook.

So if you get the same problem try out the first and if it doesn’t work then the rest of them. However, resting the navigation pane might mess with your favorite settings, but that’s not much of an issue.


  1. Thanks a lot.

    I was having the same problem. The first tip itself worked for me too.
    Did you dig any further to find why and how this problem had crept up?
    In case you did, please enlighten us.
    Thanks, again.

  2. I also want to thank you. Your first tip helped worked for me. I would like to know why this happened in the first place if you know.

  3. Ran the ” /resetnavpane” and it worked perfectly. Many thanks. I tried everything including starting from the .exe file, uninstall and install and running the repair utility. Nothing else worked.

  4. thank you! the first one did it for me. just a question, do you know why it happened? thanks again.

  5. This did not work for me. When I tried ran Outlook.exe /resetnavpane, the same error appeared, “Cannot Start Microsoft Outlook”.

  6. Here, finally is one CLEARLY and CONCISELY written solution that worked. The first recommendation worked for me. Thanks Ashish.

  7. It worked great. Thanks! One note, though… At first I didn’t notice there was a space between “Outlook.exe” and “/resetnavpane”, and that seemed to be an important detail.

  8. I had this problem, but I also have a proble with Word Excel etc not opening any existing Documents, claims they are corrupt! Any ideas?

  9. Thank you so much!!! Resetnavpane worked instantly! I noticed someone didn’t notice a space in the command at first… It’s hard to catch every space/character in long commands. When possible, just copy and paste into Run command line. Thanks again!

  10. Worked great, but only after reading Judd’s post to put the space between “Outlook.exe” and “/resetnavpane”

    The “Start>run” command has to be enabled in Windows 7. Simply right click on Windows 7 Start Menu, select properties, click customize, scroll down and locate Run Command, enable by checking, click ‘ok’ and ‘apply’ and save settings. This should bring up the ‘Run Command’

  11. thank you so much,your first solution worked…but only after leaving space between outlook.exe and /resetnavpane…..

    thank you very much…..from namibia

  12. Yay! Solution #1 worked. Hope I didn’t screw up by installing Registry Booster which was recommended on a different site.

  13. thanks, the first tip worked for a short while but each time i re-start the computer, the same error happens again… is there any other option to make the solution more long term?

  14. Thanks Dear Brother, i had problem in opening mocrosoft out look.

    as i have seen in your post Outlook.exe /resetnavpane i did its fixed my outlook.

    Thank You so much.
    God Bless

  15. I did a copy and paste and it worked immediately. Thanks so much. Don’t know why this happened but I now don’t have to spend hours with tech support tomorrow.

  16. Had this problem this morning, Microsoft’s page didn’t help any. Tried this and worked right away. Thanks so much for the help!

  17. This worked in the sense that Outlook starts up now, but! It restored an older PST file and I lost several months of emails! Whats up with that? Is there any way to get them back?

  18. Hello,

    the porblem solved wthout any lost any of mail.

    but my advice backup your .PST before

    Mohammed Ektifan

  19. Nice!!!

    The first tip worked like charm…

    But users must note the is a space between the .exe and the /


  20. Hi,

    Fantastic blog! I truely love how it’s easy on my eyes as well as the details are were written.My problem was solved,I am very happy…

    Thanks a ton!!!


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