Fix Outlook Has Stopped Working: Step-by-Step

If you see the error “Microsoft Outlook has stopped working” when you try to open the app or while you’re using it, the problem is usually a damaged profile, a faulty add-in, or a corrupted data file. This guide walks you through the most effective fixes, from quick restarts to repairing your Outlook data file, so you can get back to your email without losing your messages.

What You’ll Need

Access to your Windows desktop (Outlook is a desktop app; the steps differ slightly if you use Outlook on the web).
Your Windows login password (for some steps that require admin rights).
If Outlook won’t open at all, you may need to use the Control Panel to repair Office.

Step-by-Step

Restart your computer and try again. This clears temporary glitches and frees memory that Outlook may need. If Outlook opens after a restart, you’re done.
Run Outlook in Safe Mode. Press Win + R, type outlook.exe /safe, and press Enter. If Outlook opens without the error, a third-party add-in is likely the culprit. Skip to Step 4 to disable add-ins. If it still crashes, close Outlook and continue.
Disable add-ins. In Outlook, go to File > Options > Add-ins. At the bottom, next to “Manage,” select COM Add-ins and click Go. Uncheck every add-in in the list, then click OK. Restart Outlook normally. If it works, re-enable add-ins one by one to find the one that causes the crash.
Repair your Outlook data file (.pst/.ost). Close Outlook. Open the Control Panel > Mail (or Mail (32-bit)). Click Data Files, select your account, and click Open File Location. Note the file path. Then open the Start menu, search for scanpst.exe (it’s usually in C:\Program Files\Microsoft Office\root\Office16\ or similar). Run it, browse to your .pst/.ost file, and click Start. Let it repair any errors, then try opening Outlook again.
Repair Office installation. Go to Control Panel > Programs and Features. Find Microsoft Office in the list, right-click it, and choose Change. Select Quick Repair first (it’s faster). If that doesn’t help, repeat and choose Online Repair (requires internet and may take longer). Restart your PC afterward.
Create a new Outlook profile. In the Control Panel, open Mail > Show Profiles. Click Add, give it a name, and set up your email account again. After creating it, select Always use this profile and choose the new one from the drop-down. Launch Outlook; if it works, you can delete the old profile later.
Check for Windows updates. Go to Settings > Update & Security > Windows Update and click Check for updates. Install any pending updates and restart. Sometimes a recent Windows update can conflict with Outlook, and a newer update fixes it.

Common Mistakes

Skipping Safe Mode. Many users jump straight to repairing Office, but if an add-in is the cause, a full repair won’t help. Always test Safe Mode first.
Deleting your .pst file. That file contains all your emails, contacts, and calendar items. Deleting it is permanent data loss. The repair tool (scanpst.exe) is safe; deletion is not.
Using the wrong scanpst.exe. If you have 64-bit Office, use the 64-bit version of scanpst. Using the wrong one may not find your data file.
Not closing Outlook before repairing. The repair tool can’t access the data file if Outlook is still running. Make sure it’s fully closed (check the system tray for the Outlook icon).
Ignoring add-ins after Safe Mode works. If you don’t disable the problematic add-in, the crash will return. Take the time to isolate it.

Tips

Keep your Office updated. Regularly run File > Office Account > Update Options > Update Now to get fixes for known crashes.
Use the built-in Inbox Repair tool regularly. If you notice Outlook becoming slow or behaving oddly, run scanpst.exe before it crashes completely.
Back up your .pst file. Copy it to an external drive or cloud storage periodically. That way, even if the file gets corrupted, you can restore it.
Create a new profile before deleting the old one. Always make sure the new profile works and has all your data before removing the old one.

Troubleshooting

If you’ve tried all the steps above and Outlook still crashes, try these additional checks:

Check if the problem is with a specific email account. If you have multiple accounts, temporarily remove one (via File > Account Settings) and see if Outlook opens. If it does, that account’s settings or server might be the issue.
Look at the Windows Event Viewer. Search for “Event Viewer” in the Start menu, go to Windows Logs > Application, and look for errors with source “Outlook” or “Application Error.” The details may point to a specific DLL or module causing the crash, which can help you search for a targeted fix.
Try a different Windows user account. Create a new local user account (Settings > Accounts > Family & other users) and try opening Outlook there. If it works, your original user profile is corrupted.
Run the Microsoft Support and Recovery Assistant. Microsoft provides a free tool (SaRA) that can automatically diagnose and fix Outlook issues. Download it from Microsoft’s official site and run it for Outlook.
Reinstall Office completely. As a last resort, uninstall Office from Control Panel, restart, and reinstall from your Microsoft account. This is time-consuming but often resolves persistent crashes. Make sure you have your product key or account credentials.

Frequently Asked Questions

Will repairing Outlook delete my emails?

No. Repairing your data file (scanpst.exe) or repairing the Office installation does not delete your emails. It only fixes corrupted parts of the program or data file. However, always back up your .pst file before running repairs, just to be safe.

Why does Outlook keep crashing when I open a specific email?

That email might contain a corrupted attachment or a malicious script. Try opening it in Outlook on the web (if your account supports it) and delete it from there. If you must keep it, forward it to yourself after stripping attachments.

Can I prevent this error from happening again?

Yes. Keep Office and Windows updated, avoid installing too many third-party add-ins, and regularly run scanpst.exe if you notice slowdowns. Also, make sure your mailbox isn’t over its size limit; a bloated .pst file can cause crashes.

What is the difference between a .pst and .ost file?

A .pst (Personal Storage Table) is used for POP/IMAP accounts and stores a copy of your data locally. An .ost (Offline Storage Table) is used for Exchange/Microsoft 365 accounts and is a cached copy that syncs with the server. Both can be repaired with scanpst.exe.

Why does Outlook crash in Safe Mode too?

If Safe Mode also crashes, the problem is likely not an add-in but a corrupted data file, a damaged Office installation, or a conflict with Windows. Proceed with the repair steps (scanpst, Office repair, new profile) in that order.

Do I need to be an administrator to fix Outlook?

Most steps, like running scanpst or repairing Office, require administrator privileges. If you’re on a work computer, contact your IT department if you don’t have admin rights.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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