I was able to connect and display the desktop on my LG TV before upgrading to 8.1. Since upgrading whenever I connect to the TV only the actual desktop is displayed, but neither any open windows nor the mouse can be seen. Selecting icons on the PC shows that they are depressed on the TV, but no windows are displayed. If I switch to the tiles screen, they cannot be seen at all on the TV, which just displays a blue screen.
I have updated the HD4000 drivers to 10.18.10.3379 automatically from the device manager, but cannot find anyway to download and update them manually. Is this a common problem - any ideas to resolve are welcome ?
I am sorry to hear you are having problems.
I recommend you checking the display mode set in your computer. Based on your description, It seems that the issue can be related to the display modes so make sure the display mode is clone so you can see images in both screens and also I recommend you playing with the resolution in the computer to make the image fit on the tv.