Hello ty,
According to the description, you can refer to the following steps to troubleshoot this issue:
1.Check if you have the proper system prerequisites via the link below:
Software requirements for Office 365
2.Check if the connection to the Internet is lost during the installation.
After you regain a connection, you can run Office 365 desktop setup again at this link:
Set up your desktop for Office 365
3.Make sure you are running the latest version of Windows Installer service which is a required component to run Office 365 desktop setup.
If you do not have the latest version of the Windows Installer service, you can download it from the Microsoft Download Center.
Alternatively, you can manually update and configure desktops for Office 365.
For your reference:
Troubleshoot update and configuration issues for Office 365
Thanks,
Cherry Wang