Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hello,
Welcome to Microsoft Community and thank you for posting your query.
I suggest you to create new Windows User account and check if Office 365 installation works as expected.
Kindly refer the following link to create new user account.
http://windows.microsoft.com/en-us/windows/create-user-account#create-user-account=windows-7
Once the new User account is created, sign out of old account, and sign-in to new User account to check if Office 365 installs as expected.
You may also refer to the information mentioned in the following Microsoft article for more information.
I hope the above information helps. Let us know if you need further assistance.
Thank you.