The very first thing I'd try and do in your situation is going to Device Manager>Network Adapters>Intel Wireless-N 7260>Properties>Advanced and look thoroughly at current card settings. Probably, you'll have to pick up a different mode for it manually...
You can verify which radio type you're currently using by opening a Command Prompt window, and typing the "netsh wlan show interfaces" command. This will list the current radio type in use, your current receive/transmit rates, as well as other useful information.
For example, if you're connected to an 802.11b network, even if your adapter is 802.11n capable, it will show "802.11b" as your current Radio Type since that would be how you're connected.
In order for us to better assist you, we would like to have some more information:
1. What is your current router/access point brand and model?
2. Please download and run our https://downloadcenter.intel.com/download/25293/Intel-System-Support-Utility System Support Utility while connected to your network. This will scan your system, and allow us to see your current settings. Please save this report and attach it to your thread by switching to the "advanced editor" while replying, doing so will enable to attach option.
3. Are you using our http://www.intel.com/content/www/us/en/support/network-and-i-o/wireless-networking/000005544.html Recommended Settings for 802.11n Connectivity?
We look forward to hearing back from you.
We're following up on your thread since we have not heard back from you in a while.
Has your issue been resolved? If not, please provide us the information requested in our previous reply in order to continue assisting you.