If both wireless routers (AP) has LAN points on them as well, I would connect them to each other with a LAN cable (if they are close enough together). You wont be able to give both of them the same SSID and use different channels too. How many PC's do you have on the network? And, is it just for a network or for internet as well?

There's about 10 pcs that connect which are spread out. And yeah, it connects to the Internet too.

Try connecting the 2 AP with a LAN cable, I have not tested if its possible for 2 AP to comunicate or share workload and therefore I'm not 100% sure if that is possible, but I am sure there is someone that knows better than me that can help you.
 
I know with the WiFi wireless LAN card you get software to set it up as a "Soft AP", then its a wireless on your PC connecting to your AP while it accepts other PC to connect to it as well and shares with the original AP, it almost acts like a hub or switch I would say, its pretty neat.

The access points need to be on different channels and use unique SSIDs. Connect to each access point once from each wireless client. Windows will add the AP's to its Preferred Wireless Networks list and automatically select the strongest signal available.