Outlook Keeps Crashing or Freezing

Outlook crashes are almost always caused by one of three things: a corrupted profile, a bloated mailbox, or a broken add-in. Here's how to find and fix the culprit.

Step-by-step fix

1. 1
   Start Outlook in Safe Mode

   Hold the Windows key + R, type 'outlook /safe' and press Enter. If Outlook works fine in Safe Mode, a third-party add-in is the problem. Go to File → Options → Add-ins → Manage COM Add-ins → disable all, then re-enable them one at a time to find the bad one.
2. 2
   Repair your Outlook data file

   Close Outlook. Search your computer for 'SCANPST.EXE' (usually in C:\Program Files\Microsoft Office\...). Open it, browse to your .pst or .ost file, and click Start. This repairs corruption in the data file without deleting your emails.
3. 3
   Create a new Outlook profile

   Go to Control Panel → Mail → Show Profiles → Add. Set up a new profile with your email account. Set it as the default and launch Outlook. A fresh profile fixes corrupted settings that scanpst can't reach.
4. 4
   Update Outlook

   In Outlook, go to File → Office Account → Update Options → Update Now. Microsoft releases patches that fix known crashes — staying current prevents a large class of issues.
5. 5
   Archive old emails

   A mailbox over 5 GB slows Outlook significantly. Go to File → Tools → Clean Up Old Items, and archive emails older than 1 year to a local .pst file. This alone fixes slow-open and freeze issues for many users.