If Outlook is not opening, you can try the following steps to troubleshoot the issue:

1. Check your Internet connection - Make sure you have an active internet connection. 

2. Reboot your PC - Restart your computer to make sure all processes are running correctly.

3. Disable any anti-virus software - Temporarily disable any anti-virus software that is installed on your computer.

4. Run Outlook in Safe Mode - Press the Windows key + R to open the Run dialog, then type "outlook.exe /safe" and press Enter.

5. Reinstall Outlook - Uninstall Microsoft Outlook and then reinstall it from the official website.

6. Repair Office - Open the Control Panel and navigate to Programs > Programs and Features. Select Microsoft Office and click the Change button. Select Repair and follow the instructions.

7. Check for updates - Open Outlook and go to File > Office Account > Update Options. Select "Update Now" to check for any available updates.

8. Reset navigation pane - Go to File > Options > Mail. Under the Outlook Panes section, select Reset Navigation Pane.

9. Disable add-ins - Go to File > Options > Add-Ins and select COM Add-Ins from the Manage drop-down. Select the add-ins you don't need and click Remove. 

10. Run a system file checker - Press the Windows key + X to open the Power User menu, then select Command Prompt (Admin). Enter "sfc /scannow" and press Enter.

If none of these steps work, you should contact technical support for further assistance.