Our WIn7 laptop was working perfectly with a sky SR101 router unconnected to the internet but the laptop has just packed up. I tried using my home laptop running Win 10 but found that the SR101 kept sending a notification that its diagnostics had detected that the (non-existent) internet connection had failed. This seems to be a result of moving to Win10. The popup notification interrupted the polling of the tablets until the notification was closed down.
So I am about to try our old Talktalk router instead.