Getting a PC type laptop do connection sharing is doable with some versions of Windows but tricky to setup and not something that I recommend and I'm a tech.
I use a wireless bridge for a solution this situation. I think I paid $80 for mine. The one in my family room gives me 4 ports for my TV, my receiver, my PS3, and my HTPC. I have another in my master bedroom to feed my LG BD-370 and a planned media tank. It works great.
I have a DLink DIR-825 802.11N router and the two bridges that I bought for the two rooms were
DLink DAP1522. I find them easiest to configure manually than the one touch setup (which never worked for me). But they are tricky to configure. There is a definite trick to it that takes too long to detail unless someone really wants to know.
FWIW I like the combination router and bridge that chose because they are both dual band. I set the bridges to run on the 5ghz band and my laptop on the 2.4ghz band which means that both have access to the full 802.11N bandwidth. Overkill but I like overkill.
