Dropping Internet connection

Hi guys.
I moved to a new house. I have computers in two rooms. One desktop and one laptop per room.
Let's call the room A and B.
In room A I have Comcast Modem, as I have a business account, I'm using a Gateway Modem. I have a wired router LinkSys connected to the modem. This router has the configuration for my static IP address. I have a wireless Netgear router connected to the LinkSys router. This has been my configuration that I have been using in my old house.
Now, in room B my Internet connection drops every a while and come back again.

THis a what I have been doing to resolve my problem:
- I changed the LinkSys wired router by other and nothing.
- I disconnected the LinkSys y connected the NetGear directly to the Comcast Modem and nothing
- I changed the NetGear by other NetGear and nothing
- I change my computer to use static IP instead dynamic one and nothing.
- I got a new LinkSys UltraN wireless router and nothing.

I don't know what else to do. The desktop computer in room B keeps telling that my wireless signal is either Fair or Poor, even using the UltraN LinkSys.
Please, help me with that, I have been fighting we this for almost two weeks. Is impossible for me to work in my computer while it's dropping the connection every a while.
When I lost Internet all I have is a yellow triangle over the Network icon and it says "Local access only"

Thank you