Farther down the page of threads on this forum is one titled, "7260AC Disconnecting every 5 minutes".
Go to post #4 in that thread and download the driver linked there. It's a self-executing zip file that will open three folders for the versions of Windows. First, go to Control Panel and uninstall ProSet. Restart the PC. Click open the driver file and save somewhere on the PC. Open the adapter properties in Device Mgr. and click to update driver. Point to the Win 7 folder of the expanded driver file and let it update. Give that a go.
With the exception of Preferred Band, your driver settings are the same as mine. I don't believe that that one would make a difference.
If the 17.12 driver doesn't help, then the problem almost surely lies with the router. Do you have any kind of filtering set?