Can you further describe what is happening?
Does the viewer unable to discover the primary machine?
Or did you manage to discover and connect but disconnects immediately?
Did you get any error code/info on the viewer when it disconnects?
Did you notice any error notification in primary machine upon connection attempt?
Are both primary machine and iPhone device connected on the same local area network? with reliable/stable connection?
For further analysis, could you please run dxdiag.exe on your primary machine, click "Save All Information", save the output file (dxdiag.txt) then attach it on your next reply.