How does windows prioritize what AP to connect to if multiple are available for the same SSID?

Question

I'm wondering, I administrate a setup where we have multiple AP's feeding the same SSID on 2.4ghz and 5ghz frequencies.

Without access to anything but the dBm how could I determine what frequency / AP it was connected to?

Here's what the network looks like from Computer A

AP-1:  
SSID-Name: Our_Guest_Network
Protocol: 802.11n
5ghz: -53 dBm   300m/s
2.4ghz: -84dBm  130m/s

_

AP-2:
SSID-Name: Our_Guest_Network
Protocol: 802.11n
5ghz: Not detected (due to distance) 
2.4ghz: -33dBm 130m/s

Any help understanding which AP a Windows 7 system would route traffic to and why would be useful.

Thanks,