Im sorry im basically a nub when it comes to wireless networking. What is a AC based Router and card? My ISP wants us to use the router/modem that they provide. Believe me, Ive tried getting them to let us use our own router. I recently just moved out here and its a huge step down from where I used to live.
I got into our routers setup site and changed the channel to 11 but only see I slight gain in speeds on the PC, up to about 2.5 Mbps.
I dont get how my laptop runs fine right out of the box but no matter what card or usb adapter I try on my pcs it doesnt.
Both of the adapters you've tried in your PC have been 2.4Ghz only. It sounds like it'll be connecting over the 54Mbps "G" standard as you only see one channel (currently 11) on the router config. Your WiFi card is capable of using 2.4Ghz wireless "N" which allows up to 300Mbps by using 2 channels bonded together, but this needs to be set on the rotuer (e.g. channel 1 & 6). Chances are your router doesn't support this 2.4Ghz channel bonded "N" standard. If it does turn out to have this enabled, I'd suggest you try setting it to b/g only mode, and disable the N mode to see if that helps.
Confusingly there is also an N standard for the 5Ghz frequency that is not channel bonded, just a single fast channel on a nice clean frequency.
The 2.4Ghz frequency is often heavily congested, and you may find your issues are caused by interference from nearby WiFi networks (not helped if the router is weak). From experience, the 2.4Ghz "N" standard is terrible and usually results in worse performance if you have any interference issues like this. A good solution is to get a "dual band" adapter, capable of using the 5Ghz frequency, as this is normally much less congested. Example:
http://www.amazon.com/dp/B005JJS7IY/?tag=neogaf0e-20
Your laptop may already be connecting over the 5Ghz frequency. It's worth checking the router config to see if the same SSID name is used for both the 2.4 and 5Ghz networks. If it's the same SSID, the adapter will usually connect to 5Ghz, but drop down to 2.4 if it loses signal. Be a bit careful when changing this, some routers only support 2.4 OR 5ghz, not both simultaneously. It'll be clear from the router config if this is the case. If you set it to just use 5Ghz on the router it will prevent devices only capable of 2.4Ghz from connecting.
Sorry to ramble on a bit, hope it helps! I ended up switching most of my kit to 5Ghz and home plugs for longer distances after facing similar problems. If you can't enable both 2.4 and 5ghz networks on the router, and can't change the router, it's time for plan B. You could get a pair of home plugs to connect your PC to the router via ethernet. You can easily achieve a 100Mbps connection this way. Or you could see if you have an option to set the crummy ISP router into a modem only mode, and have it act as a modem for your own router (so still technically using the ISP kit).