There are 2 types of 7260 N according to Intel's WiFi products list : Intel® Wireless Product Selection Guide
If yours doesn't have the word "Dual Band" then it most likely doesn't have 5 GHz capability.
To see what radio types are supported with your 7260N type the following on the command prompt:
netsh wlan show drivers
Pay attention to the radio types. If you see the word, 802.11a it means you have 5 GHz capability. If not then you don't have it.
Hope this clears up your issue.