Manifold traditional topology tools come in as an msi package. In some scenarios, even though one has an admin account, it will not be possible to install the topology tools. This thread mentions that this is because a built in admin account is requires to complete the installation process successfully.
A workaround is to launch a cmd as an Administrator and from there execute the:
msiexec /a Manifold-Traditional-Topology-Tools-126.96.36.199-x64.msi
That should do the trick.