pms not showing on renders

[princeofthepc]

i know this question has been asked dozen of times but i followed the FAQ and googled the problem with no success
i am running windows 8 the problem is the server is visible sometime and most of the time it is not
while i have twnoky( another media server that is working and streaming all the time)
note:i also tried samsungallshare media server and it is visible when pms is visible only