Software & Apps MS Office What to Do When Microsoft Outlook Won't Open Troubleshooting Microsoft's email application By Tricia Goss Writer Tricia Goss has been a writer and editor for 10+ years. She's written tips and tutorials for Microsoft Office applications and other sites. our editorial process Facebook Twitter LinkedIn Tricia Goss Updated March 17, 2020 MS Office Outlook Word Excel Powerpoint Tweet Share Email If Microsoft Outlook won't start, don't despair. Getting your email client back up and running properly might be simpler than you think. The right fix will depend on what you are experiencing as well as the version of Microsoft Outlook you have installed. Here's how to troubleshoot and repair your Microsoft Outlook. Lifewire / Miguel Co The first set of suggestions here applies to Outlook 2019, 2016, 2013, or 2010 for PCs. The second set of suggestions applies to Outlook for Mac 2016 or Outlook for Mac 2011. Troubleshooting Outlook on a PC The following troubleshooting techniques apply to PCs running Microsoft Outlook 2019, 2016, 2013, or 2010. Try Disabling Add-Ins One or more add-ins could be conflicting with Outlook and causing the problem. Disable all add-ins and see if this resolves the issue. You'll need to be able to open Outlook in Safe Mode to use this troubleshooting technique. Start Outlook in Safe Mode. Select File. Select Options. Select Add-ins in the left pane. Make sure COM Add-ins is selected in the Manage box at the bottom of the Outlook Options window. Select Go. Write down or take a screenshot of the list of the add-ins before you disable them. Clear all of the selected checkboxes in the COM Add-ins list. Select Remove. Select File and choose Exit. Open Outlook and see if this has solved the problem. If Outlook still isn't opening, move on to another troubleshooting technique. Try Repairing Outlook It's possible your Outlook application is damaged. Use the built-in Microsoft Office repair utility to fix it. The process varies slightly for Windows 10, Windows 8, and Windows 7. Repair Outlook in Windows 10: Close all Microsoft Office applications. Type Apps & Features into the Windows search box. Select Apps & Features. Find and select Microsoft Office in the list of installed apps and features. Select Modify. Select Yes if a user account control window appears asking, "Do you want to allow this app to make changes to your device?" Select Online Repair and then the Repair button. Restart Outlook when the repair process is complete. If Outlook still won't open, try another troubleshooting technique. Repair Outlook in Windows 8: Close all Microsoft Office applications. Right-click the Start button. Select Control Panel. Make sure Category is selected in the View By list. Click Uninstall a Program under Programs. Right-click Microsoft Office and choose Change. Select Online Repair if it is available (this depends on the type of Microsoft Office you have installed). Select Repair. Select Yes if a user account control window appears. Restart Outlook when the repair process is complete. If Outlook still won't open, try another troubleshooting technique. Repair Outlook in Windows 7: Close all Microsoft Office applications. Select the Start button. Select Control Panel. Make sure Category is selected in the View By list. Select Uninstall a Program under Programs. Select Microsoft Office from your list of programs. Select Change. Select Online Repair if it is available (this depends on the type of Microsoft Office you have installed). Select Repair. Select Yes if a user account control window appears. Restart Outlook when the repair process is complete. If Outlook still won't open, try another troubleshooting technique. Create a New Profile Outlook profiles can become corrupted, causing all sorts of problems, including Outlook not opening. Creating a new profile and setting it up with your email account can solve the problem. You will need to be able to start Outlook in safe mode to perform this procedure. Select File. Select Account Settings. Choose Manage Profiles from the drop-down list. Select Show Profiles. Select Add. Type a name for the new profile in the Profile Name box and select OK. Follow the prompts to set up your email account in the new profile. Restart Outlook. Select File. Select Account Settings. Choose Change Profile from the drop-down list. Select OK on the Outlook Will Close message. Restart Outlook. Choose the name of the new profile you created in the Profile Name list and select OK. Try opening Outlook to see if this has solved the problem. If not, try another troubleshooting technique. Repair Outlook Data Files If Outlook still won't open, use the Inbox Repair tool to find and possibly fix the problem. Navigate to the file location that corresponds to your version of Outlook. Outlook 2019: C:\Program Files (x86)\Microsoft Office\root\Office16Outlook 2016: C:\Program Files (x86)\Microsoft Office\root\Office16Outlook 2013: C:\Program Files (x86)\Microsoft Office\Office15Outlook 2010: C:\Program Files (x86)\Microsoft Office\Office14 Scroll down to SCANPST.EXE. Double-click SCANPST.EXE to open it. Make sure your Outlook data file is listed as the file you want to scan. If not, select Browse and navigate to your data files. Select Start to begin the scan. Select Repair to fix any problems found. Try opening Outlook to see if this has solved the problem. If not, try another troubleshooting technique. Reset the Navigation Pane A startup issue with the navigation pane can prevent Outlook from opening correctly. Resetting the navigation pane might resolve the issue. Press the Win + R keys on your keyboard to open the Run command. Type Outlook.exe /resetnavpane in the Open box and click OK. Try opening Outlook when the process is complete to see if this has solved the problem. Troubleshooting in Outlook 2016 and 2011 for Mac The following troubleshooting techniques apply to Outlook 2016 for Mac and Outlook 2011 for Mac. Check for Updates A recent update could include a fix for the problem of not being able to start Outlook. Check for and install any available updates, even if you cannot open Outlook. Open any other Office application, such as Word or Excel. Go to Help. Select Check for Updates. Select Automatically Download and Install under "How would you like updates to be installed?" Select Check for Updates. Rebuild the Outlook Database Using the Microsoft utility to rebuild a corrupted database might solve the problem of Outlook not opening on your Mac Please note if you have a Microsoft Exchange account, rebuilding the database will delete any information not synced with the server. Back up any Outlook data stored only on your computer before you rebuild the database. Quit all Microsoft Office applications. Hold down the Option key and then select the Outlook icon in the Dock to open the Microsoft Database Utility. Select the identity of the database you want to rebuild. Select Rebuild. Restart Outlook when the process is complete. Office 365's Support and Recovery Assistant If you are using the cloud-based Office 365 on a PC or a Mac, download and use the automated Support and Recovery Assistant tool to diagnose and fix many issues, including the problem of Microsoft Outlook not starting.. Download the Support and Recovery Assistant application from Microsoft. Run the installation. After it's installed, the Support and Recovery Assistant will automatically start. Agree to accept the license agreement. Choose Outlook as the program you want help with. Select Next. Select Outlook Won't Start and then Next. Select Yes to confirm you are using the affected computer, followed by Next. Enter the email address and password you use for Office 365 and click Next. Wait while the app diagnoses your problem. Review the results when the assistant is finished. Follow the prompts and exit the tool if it repairs Outlook. Check for suggestions of other solutions if the tool is not able to correct the problem.