When installing MS Office on a Samba drive for which you have admin user permissions, ie. admin users = username, you will find the setup program unable to complete the installation.
To get around this problem, do the installation without admin user permissions The problem is that MS Office Setup checks that a file is rdonly by trying to open it for writing.
Admin users can always open a file for writing, as they run as root. You just have to install as a non-admin user and then use "chown -R" to fix the owner.