Edit:- piped by hayden.. but here is my 2cents also...
Without using addtional cabling, you essenitally have 2 options.
Wireless:-
If your TV is within range of the pc's wireless mouse/heyboard/controllor then you may be able to use somehting like this
http://www.marmitek.com/en/product-deta ... ew-821.phpIt is a wireless 1080p 3D hdmi signal sender reciever kit, range will reduce as resolution/refresh goes up.
Note devices operating on 2.4ghz and 5ghz frequencys can often effect wireless network signals
Mains/Powerline:-
http://www.digisender.net/documents/man ... UK_Web.pdfSimilar to the wireless device only this uses the existing mains/powerline cabling in your house, it uses the 50/60hz mains frequency as a carrier by modulating the video signal with it.
This should prove to be more reliable than wireless however note that different electrical rings in the house can cause issues impacting on performance, same electrical rings are recommend, I use a set of the powerline networking adaptors that work across different electrical rings, but they do not operate as fast as they could, ie about 60%.
Note that both of these will apply a small amount of latency which may make the experience feel laggy in terms of responsiveness.
They are genrally aimed at stremaing video, rather than aimed at remote pc gaming where latency is a killer.
With using addtional cabling you have a few other options.
Use a Cat5 HDMI transmitter, these devices allow you to transmit HDMI 1080p up to very long distences with minimal latency of 1 video frame.
Some of these units support reverse direction IR so that you could potentialy use a IR wireless mouse and keyboard.
such as this one
http://www.lindy.co.uk/hdmi-ir-cat6-ext ... 38002.htmlNote this cannot plug into the home network, it is an end to end connection with a dedicated cable, it will not work alongside convential pc data traffic.
Cat5/6 cabling is also a lot easier and cheaper to run than thicker more expensive hdmi cable.
Alternatively if you are laying cables you can use conventional extention cables.