The full list of supported operating systems for View 5.1 Agent is shown on page 15 of the installation guide - http://pubs.vmware.com/view-51/topic/com.vmware.ICbase/PDF/view-51-installation.pdf - see the section on Supported Operating Systems for View Agent.
You will find information on this forum from people who have got Windows 8 working and avoiding the "black screen" "The connection to the remote computer ended", but note that this is not supported with View 5.1.x.
Mark