Hi, Hope this is in the correct section

I have a small problem under the Devices and Printers option

I have 2 external devices (Xbox 360 & BluRay Player), these devices are shown in Windows as Offline (even when turned on), so when I try and to a 'Play To' it says no devices

If I go into Devices and Printers and click Add a Device they then go on line and can be used, until I power then Off/On for next time

Any idea why Windows doesn't automatically make this available?

All devices are on WiFi
I am using a Dell Inspiron Laptop on Win 8.1 with all the latest updates