Out look and microsoft excel not opening

Run an Online Repair of Microsoft 365 or Office, because it repairs the entire Office installation containing both Outlook and Excel rather than only the application displaying the message.

Repair Microsoft 365 or Office

1. Close Outlook, Excel, and all other Office applications.
2. Open the repair settings:
   • Windows 11: Right-click Start → Installed apps.
   • Windows 10: Right-click Start → Apps and Features.
3. Find Microsoft 365 or Microsoft Office.
4. On Windows 11, select the three dots beside it, and then select Modify. On Windows 10, select the product and then Modify.
5. If the installation is Click-to-Run, select Online Repair → Repair. This is more comprehensive than Quick Repair.
6. If an MSI-based repair window appears instead, select Repair → Continue.
7. Complete the prompts and restart Windows when finished.
8. Open Excel and Outlook normally and test them.

This repairs the whole Office suite even when only particular applications are failing. Online Repair requires an Internet connection and can take longer because it performs the more complete repair process.^1^

If Online Repair does not resolve it

Test each application in Office Safe Mode, which starts it without most add-ins:

1. Press Windows key + R.
2. Enter the following command for Excel:

excel /safe

3. Repeat with Outlook:

outlook /safe

The space before /safe is required. If an application opens in Safe Mode, an add-in is likely interfering with normal startup.^2^

For each application that opens in Safe Mode:

1. Select File → Options → Add-ins.
2. At the bottom, select COM Add-ins under Manage, and then select Go.
3. Record or take a screenshot of the enabled add-ins.
4. Clear their check boxes—disable them rather than selecting Remove.
5. Close and reopen the application normally.
6. If it now works, enable add-ins individually and restart the application after each one. Leave disabled the add-in that causes the error to return.^3^

If neither Outlook nor Excel opens in Safe Mode after Online Repair, the next supported path is to uninstall and reinstall Office.^4^

References

1. Repair an Office application | Microsoft Support
2. Open Office apps in safe mode on a Windows PC | Microsoft Support
3. I can’t start Microsoft Outlook or receive the error “Cannot start Microsoft Outlook. Cannot open the Outlook Window” | Microsoft Support
4. I get a "stopped working" error when I start Office applications on my PC | Microsoft Support