Hi,
There can actually be limits to what the "administrator" user on a Windows system can do, in this case you need to grant the special "Log on as a service" rights to your user. On my system that can be done e.g.:
Start -> Administrative Tools -> Local Security Policy, then:
Local Policies -> User Rights Assignment, then:
Log on as a service
Make sure your user is added to the list and then it should be possible to specify that user to the Multi-Hypervisor Manager Server and complete the installation.
HTH,