Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Dear Karim,
Good day! Thank you for posting to Microsoft Community. We are happy to help you.
Per the description shared, I would like to summarize your concern i.e., when you are trying to install the Office apps you are encountering an error.
If my understanding is correct, based on the error message, I suggest you to temporarily turn off the proxy, antivirus, firewall, or VPN if enabled and re-install the Office apps.
If the above services are not enabled, please check whether any previous Office apps are installed on your device? Please go to the Control Panel> Programs> Programs & Features> Check whether any other Office apps version is installed.
If the same problem persists, can I know the name of the Office 365 Subscription using at your end?
We look forward to your response. Thanks for your cooperation.
Sincerely,
Mia | Microsoft Community Moderator