Samsung TV Connection Confusion

Hi there

I am trying to connect my PC running XP and my Samsung TV and am finding it rather confusion. I have four devices on my network and they can each connect to different devices and I am not sure why

Device 1: PC (LAN) running XP and Serviio. Cannot see any other device
Device 2: Laptop (wifi) running Windows 7 & Serviio. Can connect to PC, and TV
Device 3: Samsung S2 phone (wifi) running ICS & allshare. Can connect to PC, laptop and TV
Device 4: Samsung TV UE32ES5500K (LAN) running allshare. Can play media from the phone and the laptop but not the PC

I am confused as to why my PC is being so problematic in what devices it will connect with. Ultimately i would like to play media on my PC on my TV.

Any advice would be greatly appreciated.

Thanks

Andy

[zip]

MIght be firewall/antivirus blocking it. Also they should be on the same subnet.