Having moved into my new place, and finally setting everything up to have a play on my new 'Fallout' gaming rig. All plays well and works well, until I go to play on my new LAN setup. The wireless adapter keeps disconnecting itself from the network, unhitching any LAN game running at the time. I have gone into everywhere and looked at all settings, and everything seems to be fine, although I am no networking guru, I can get simple things up and running.
The setup is as follows;
(upstairs setup)
1 x Server 3.0Ghz Dual Core 4gb DDR2 800 (used for games that can have a dedicated server)
1 x 'Half-Life BLUe' gaming rig
1 x TP-Link TL-WR642G Wireless 4 port Router

these two machines are connected via port 1 (Server) and port 2 ('BLUe') on the router.

(downstairs setup)
1 x 'Fallout' gaming rig (connects via the AC-66 wireless adapter)

distance between the two machines would be less than 15 feet or 3 and a bit meters, line of sight, ignoring walls etc.

The problem is whenever I try to get the downstairs machine to connect to the upstairs router, it won't stay connected for roughly more than 30 seconds and then drops connection. If I bring the router downstairs it will connect wireless, but has ping delay issues. If I bring both machines together and connect them via cables to the same router they work all day long.

Now here's the dilema, The Asus AC-66 wireless card can connect to the upstairs ADSL2+ modem no problems at all, no drop outs and full speed and the ADSL2+ modem is right next to the LAN router?!? ... 'Has to be a weak signal from the router' I hear you all cry ... well then, explain how any laptop can connect to the LAN network straight away wether it is downstairs, upstairs or anywhere, while the AC-66 card cannot?

I have tried the card with the aerials in the back of the card, on the aerial base, move the base around ... nothing seems to get this thing to want to connect for anything that could even be called 'a length of time'

I was under the impression that this card was the best, and I still have faith in it, but when you see an el cheapo laptop, with what could only be a generic wireless adapter in it, connect to what the 'you beaut' card can't ... kinda makes one wonder.

any help would be greatly appreciated.
Thanks,
GUYVER.

P.s.
The current game I am 'trying' to LAN is Borderlands 1. It doesn't use a dedicated server, one of the game rigs acts as the 'server' so to speak, so only two machines are required to play this for two players. 'Fallout' & "BLUe' connect via cable and play all day long, as I mentioned, but that's not how I want the intended setup to be, it makes my living room very messy, lol.