I was able to resolve the issue by uninstalling Office 365 and then reinstalling it from my subscription. Then Outlook worked.
What to do when Outlook will not open on my PC?
Outlook suddenedly will not open on my PC. I tried the following: restarting the PC, using the repair and reset options, then uninstalled and reinstalled OUtlook. Then restarted the computer. It still does not open. What needs to be done to open Outlook?
Moderator note: Locking thread because the original poster has indicated that the problem has been fixed. Other replies mention other versions of Outlook.
Outlook | Windows | Classic Outlook for Windows | For home
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Sam Bellflowers 95 Reputation points
2025-12-07T00:16:20.7366667+00:00 -
Sam Bellflowers 95 Reputation points
2025-12-06T13:03:17.7333333+00:00 Hang tight, Colin. Other folks doing same thing. MS hasn't realized it yet. Something happened during an update. Will probably be fixed when enough users scream. In mean time, you can access direct by going to https://www.microsoft.com/en-us/microsoft-365/outlook/email-and-calendar-software-microsoft-outlook?deeplink=%2fmail%2f0%2f%3fnlp%3d0&sdf=0
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Kimberly Olaño 23,395 Reputation points
2025-12-04T13:24:37.1866667+00:00 Thanks for sharing the details, Cathy! Try to fully delete corrupted Outlook data files (.DAT, .SRS, .XML, .PST lock files)
Even when you reinstall Outlook, broken config files remain and stop Outlook from launching.
Delete Outlook’s startup configuration files
- Close Outlook completely.
- Press Win + R → paste each line one at a time:
%appdata%\Microsoft\Outlook - Delete:
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Outlook.srs -
Outcmd.dat -
Outlook.xml
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- Restart Outlook.
These files recreate automatically and often fix launch failures.
See if this helps. If you need further assistance just let me know.
Best regards,
Kimberly
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Q&A Assist2025-12-04T12:47:10.3966667+00:00 AI generated content. This question contains an answer created with AI from Q&A Assist. Learn moreIf Outlook is not opening on your PC after trying to restart, repair, reset, and reinstall, you can try the following steps:
- Check Compatibility Settings:
- Locate
Outlook.exein the installation directory (e.g.,C:\Program Files\Microsoft Office\Office16orC:\Program Files(x86)\Microsoft Office\Office16). - Right-click on
Outlook.exe, select Properties, and go to the Compatibility tab. - Ensure that the Run this program in compatibility mode for option is unchecked.
- Click OK to apply changes.
- Locate
- Perform a Clean Boot:
- Use the Selective Startup option in System Configuration to disable all non-Microsoft services and startup items. This can help identify if a background service is causing the issue.
- To do this, type
msconfigin the Run dialog (Win + R), select Selective startup and uncheck Load startup items. Then, restart your computer.
- Repair Office:
- If you haven't already, try repairing your Office installation again. Go to Control Panel > Programs and Features, select Microsoft 365, and choose Change. Then select Quick Repair.
- Check for Updates:
- Ensure that your Windows and Office applications are fully updated, as updates may fix bugs that prevent Outlook from opening.
- Create a New Profile:
- Sometimes, the Outlook profile may be corrupted. You can create a new profile by going to Control Panel > Mail > Show Profiles and adding a new profile.
If none of these steps resolve the issue, you may need to look into more specific error messages or logs to diagnose the problem further.
References:
- Check Compatibility Settings: