I live in a new home, built in December 2007 with cat5e to all rooms. Despite the fact that all the jacks were only pre-wired for RJ11 jacks and phone connections, can I upgrade the jacks to RJ45 plugs, and if so, how do I network them all together? I am only looking to wire up the jacks in three of the rooms to run HTPC sets. I have a router at one location now where my primary home computer works, but want to be able to share connections throughout the house, without having to go wireless. Is this even an option? Any help or guides to get me started, as I don’t want to have to rewire the whole house…maybe there is something that can be done at the initial junction box.
I might also point out, my ISP is WiMax, through ClearWire, not sure if this creates constraints on capacity, etc.



If you have access to all 8 wires in the wall jacks, you should be able to put in RJ-45 network jacks.
Odds are all those cables go to the one central distribution point, for the phone I assume. You have to find out where all the wires go. There is a chance they just daisy-wired some of the jacks (room to room), that is no good, you can’t wire ethernet that way.
If you find a central point for all the wires, get a punch-down block (distribution panel), and punch down the wires you need into that panel, by disconnecting the phone connections. Then you simply run patch cables from the patch panel to your switch/router, which would (has to) be located at the same location.
If you don’t mind the expense there’s always homeplug networking?
http://www.amazon.co.uk/s/?ie=UTF8&keywords=mains+network&tag=googhydr-21&index=aps&hvadid=4130439583&ref=pd_sl_8fcw4hf6gl_b
Though I understand all the relevant sockets should be on the same ring main.