If you are trying to run the installation file for X1 and you are receiving the message:
* Click "Cancel" and re-run the installation process later, when no Outlook windows are open, or
* Close all Outlook windows and click "Retry" to continue the installation."
(screenshot of message)
Sometimes Windows reports that it has closed Outlook, but mistakenly leaves the "Outlook.exe" process running.
You should be able to stop the process manually using these steps:
1. Open Task Manager (Ctrl+Alt+Delete, choose Task Manager)
2. Click the Processes tab
3. Sort by the Image Name column
4. Click on the "Outlook.exe" process from the list and then click End Process
5. Close Task Manager
6. Install X1