Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hi Andre,
Based on the description you’re not able to uninstall the Office 365 Preview.
As per the error message, the installation is damaged or corrupted, you may have to remove the Office manually.
Refer the section ‘Remove Office manually’ from the following Kb article and check if it helps:
http://support.microsoft.com/kb/2739501
Note: Ensure you have taken the backup of the registry keys before modifying it.
Let us know if this has helped you in resolving this issue.