How to Fix Outlook Start-up Errors in Windows


If Outlook doesn’t open and you see an error, the data file may have been corrupted. Here’s how to fix it.

Deleting Old Data Files

  1. Navigate to C:\\Users\username\Documents\Outlook Files.

    • Ensure you replace "username" with your Windows username.

    • If that path doesn't exist on the machine, try %localappdata%\Microsoft\Outlook.

  2. Delete everything in here, including any files with ".pst", ".nst" and ".ost" extensions.

  3. Open Run (Win + R).

  4. Type "%temp%" and press enter.

  5. A folder will open. Delete everything in here.

  6. Empty the bin.

Creating New Data Files

  1. Open Run (Win + R).

  2. Type "outlook /profiles" or "outlook /safe" and press enter. A dialog box from the Outlook app should open.

    • If you don't see a dialog box, even after trying both commands, follow steps 1-8 in the indented section below.

If you do see a dialog box, follow steps 3-5 in the outdented section below.

        1. Open Run (Win + R).

        2. Type "cmd".

        3. Press Ctrl + Shift + Enter in the Run box rather than just the regular enter/OK button to open Command Prompt as an administrator.

        4. If prompted to enter your Windows administrator password, please do so.

          • Note: You will need to run two commands in Command Prompt. It will take a while for these two commands to complete.

        5. Inside the Command Prompt window, type "dism /online /cleanup-image /restorehealth" and press enter to run an online repair.

        6. Once you see a message in Command Prompt stating that the scan is complete, type "sfc /scannow" and press enter to run a local System File Check (SFC).

        7. Repair/reinstall Office in Control Panel\Programs\Programs and Features.

        8. Start again at step 1 of "Creating New Data Files" in this article.

  1. In the dialog box, click "Options > >".

  2. Click "New…".

  3. Follow the usual process of adding a new mailbox.


You should now be able to launch Outlook without any problems. For further help, please see the official Microsoft documentation.


  • The fixes I have provided are not guaranteed to work successfully. The configuration or any limitations of your computer, network or the remote server could have an effect.

  • I am not liable for any data loss that may occur. Following these steps may cause data loss. This shouldn't happen as long as your emails can be pulled back down from the cloud correctly, which is usually the case.