Start classic Outlook in Safe Mode to bypass add-ins; if it still hangs at Loading Profile, create a new Outlook profile rather than repeating the restart, Task Manager, or Quick Repair steps already tried.
Use Outlook on the web at https://outlook.office.com while repairing the desktop application. If web access works, the mailbox remains available and the fault is isolated to classic Outlook or its local profile.
2. Test Outlook without add-ins
- Press Windows key + R.
- Enter:
outlook.exe /safe
- Select OK, choose the normal profile if prompted, and sign in.
If Outlook opens, disable its add-ins:
- Select File → Options → Add-ins.
- At the bottom, choose COM Add-ins → Go.
- Take a screenshot of the enabled add-ins, then clear their check boxes. Do not select Remove.
- Close Outlook and start it normally.
- Re-enable add-ins one at a time, restarting Outlook after each one, until the failure returns. Leave the offending add-in disabled. ^1^
3. If Safe Mode also hangs, create a fresh Outlook profile
This tests the most likely local configuration problem without deleting the existing profile.
- Hold Shift while starting Outlook.
If the profile picker does not appear, press Windows key + R, enter:
Outlook.exe /profiles
- In the profile picker, select Options.
- Enable Prompt a profile to be used so the original profile remains available.
- Select New, enter a profile name such as
OutlookTest, and select OK.
- Add the Microsoft 365 work account and complete sign-in.
- Start Outlook using
OutlookTest.
If the new profile loads, the original profile is damaged. Continue using the new one and re-add any additional accounts or settings as required. Do not remove the old profile yet: removing a profile can also remove associated local data files. ^2^ ^3^
4. Check the current Windows-update case if POP or PST files are involved
A documented issue affected Outlook for Microsoft 365 profiles containing POP accounts or PST files, particularly PST files stored in OneDrive, after the January 13, 2026 Windows updates. Symptoms include Outlook hanging and requiring Task Manager or a restart before it can reopen.
If that description matches the account:
- Open Start → Settings → Windows Update.
- Select Install now or Check for updates.
- Install everything offered and restart as required.
- Repeat until Windows Update reports You’re up to date.
Microsoft marks this issue as fixed through Windows Update. If problems remain afterward, POP profile repair or PST repair may be necessary. ^4^
5. Run the startup troubleshooter, then Online Repair
If neither Safe Mode nor a new profile works:
- Open the Windows Get Help app.
- Run the Classic Outlook startup troubleshooter and follow its findings. It requires Windows 10 or later, must run on the affected PC, and does not apply to new Outlook. ^5^
- If it finds nothing, run the deeper repair:
- Start → Settings → Apps → Installed apps
- Find Microsoft 365, select … → Modify
- Select Online Repair → Repair
Online Repair is more extensive than the Quick Repair already attempted and repairs the full Office suite. ^6^
If a fresh profile cannot be created or Outlook still will not start after Online Repair, ask the organization’s Microsoft 365 administrator to open a support request and include the startup-troubleshooter results.
References
- [Classic Outlook](https://support.microsoft.com/outlook/getstarted/outlook-for-windows-not-responding-hangs-freezes-or-stops-working)
- Create a profile in classic Outlook for Windows
- Outlook crashes or stops responding when used with Office 365 | Microsoft Support
- Classic Outlook profiles with POP accounts and PSTs hang after Windows ...
- Classic Outlook troubleshooters | Microsoft Support
- Repair an Office application