Outlook crashing repeatedly can be resolved by disabling problematic add-ins, repairing damaged Outlook data files (PST/OST), resolving conflicts with other software, updating Outlook, or fixing underlying Windows system errors. Troubleshooting involves identifying the root cause and applying the appropriate fix. This guide provides a structured approach to resolve the problem.

Identifying the Culprit: Common Causes of Outlook Crashes

Before diving into solutions, understanding the potential causes will help you narrow down your troubleshooting.

1. Corrupted or Incompatible Add-ins

Outlook add-ins are third-party applications that extend Outlook’s functionality. While useful, poorly coded or incompatible add-ins are a frequent source of instability.

  • How to identify: Outlook crashing shortly after starting or while performing specific actions (e.g., sending an email with a particular add-in enabled) is a strong indicator.
  • Related error codes: While not always present, error messages related to specific DLL files associated with add-ins can point to this problem.

2. Damaged Outlook Data Files (PST or OST)

Outlook stores your emails, contacts, and calendar in data files. PST (Personal Storage Table) files are typically used for POP3 accounts or archive folders, while OST (Offline Storage Table) files are used for Exchange, Office 365, and IMAP accounts. Corruption in these files can lead to crashes.

  • How to identify: Outlook crashes frequently, especially when accessing or searching within emails, contacts, or calendar entries. Slow performance can also be a symptom.
  • Related error codes: “Outlook data file has reached its maximum size,” or general errors related to file access.

3. Conflicting Software

Other software installed on your computer, such as antivirus programs or other email clients, can conflict with Outlook, causing it to crash.

  • How to identify: The crashes started after installing new software.
  • Related Error Codes: Errors that mention conflicting modules or DLLs.

4. Outdated Outlook Version

Using an outdated version of Outlook can lead to compatibility issues and expose you to known bugs that cause crashes.

  • How to identify: You haven’t updated Office/Outlook in a while.
  • Fix: Update to the latest version.

5. Underlying Windows System Errors

System files, drivers, or registry entries can become corrupted, affecting the stability of Outlook and other applications.

  • How to identify: Other applications are also crashing.
  • Fix: Run system file checker.

6. Hardware Acceleration Issues

In rare cases, problems with your graphics card driver or hardware acceleration settings in Outlook can trigger crashes.

  • How to identify: The crashing is random, and there are no apparent error messages.
  • Fix: Disable hardware acceleration.

Solutions: Troubleshooting and Fixing Outlook Crashes

Safety First: Before making significant changes, back up your important Outlook data.

1. Disable Add-ins

The first step is to disable all add-ins and then re-enable them one by one to identify the culprit.

  • Steps:
    • Open Outlook in Safe Mode: Press Windows Key + R, type outlook /safe, and press Enter. This starts Outlook without loading add-ins.
    • If Outlook works in Safe Mode, go to File > Options > Add-ins.
    • At the bottom, select “COM Add-ins” and click “Go…”.
    • Uncheck all add-ins and click “OK”.
    • Restart Outlook normally.
    • Enable add-ins one by one, restarting Outlook after each, to identify the problematic one.
    • Once the problematic add-in is found, remove or update it.

2. Repair Outlook Data Files (PST/OST)

Microsoft provides a built-in tool called Scanpst.exe (Inbox Repair Tool) for repairing damaged PST and OST files.

  • Steps:
    • Close Outlook.
    • Locate Scanpst.exe (typically found in C:\Program Files\Microsoft Office\root\Office16, but the exact path varies depending on your Office version).
    • Run Scanpst.exe.
    • Browse to select the PST or OST file you want to repair (the default location is C:\Users\%username%\AppData\Local\Microsoft\Outlook).
    • Click “Start”.
    • If errors are found, click “Repair”.
    • Once the repair is complete, try opening Outlook again.

Important: It’s highly recommended to back up your PST/OST file before running Scanpst.exe.

3. Check for Conflicting Software

Temporarily disable potentially conflicting software, such as antivirus programs (carefully!), to see if it resolves the issue.

  • Steps:
    • Disable your antivirus program.
    • Start outlook.
    • If it works, consider adding Outlook to the antivirus program’s exclusion list.
    • Remember to turn your antivirus back on afterwards.

4. Update Outlook

Ensure you have the latest updates for Outlook installed.

  • Steps:
    • Open Outlook.
    • Go to File > Account > Update Options > Update Now.
    • Follow the on-screen instructions to install any available updates.

5. Repair or Reinstall Office

If updating doesn’t resolve the issue, try repairing your Office installation.

  • Steps:
    • Open Control Panel > Programs > Programs and Features.
    • Find Microsoft Office in the list, right-click on it, and select “Change”.
    • Choose “Quick Repair” or “Online Repair” (Online Repair is more thorough).
    • If repairing doesn’t work, consider reinstalling Office.

6. Run System File Checker (SFC)

The System File Checker tool scans for and repairs corrupted system files.

  • Steps:
    • Open Command Prompt as administrator (right-click on the Start button and select “Command Prompt (Admin)” or “Windows PowerShell (Admin)”).
    • Type sfc /scannow and press Enter.
    • Wait for the scan to complete (this may take some time).
    • Restart your computer.

7. Disable Hardware Graphics Acceleration

  • Steps:
    • In Outlook, go to File > Options > Advanced.
    • Under the “Display” section, check the box “Disable hardware graphics acceleration.”
    • Restart Outlook.

Frequently Asked Questions

Why does Outlook keep crashing even after I restart my computer?

Restarting doesn’t address underlying issues like corrupted data files or incompatible add-ins. Follow the troubleshooting steps in this guide to identify and fix the root cause.

How do I back up my Outlook data files before running Scanpst.exe?

Locate your PST/OST file (usually in C:\Users\%username%\AppData\Local\Microsoft\Outlook). Copy the file to a safe location, such as an external drive or another folder on your computer. This creates a backup in case something goes wrong during the repair process.

Will repairing or reinstalling Office delete my emails and other Outlook data?

Repairing typically doesn’t delete data, but it’s always wise to back up your PST/OST files. Reinstalling can remove data, so ensure you have a current backup before proceeding.