Hi, Thanks for your reply.
I tried adjusting the TV settings and came across a spec on the LG website saying that the TV has a refresh rate of 50Hz. I checked the Windows display settings and it was showing as 30Hz. I tried setting it at 60Hz but got a much enlarged and distorted screen all in pink! However, I’m in the UK so think 50Hz is standard here. I changed it to 50Hz and got back to where I was before but with the taskbar disappearing.
I then right clicked on my desktop and got the NVidea display settings for my graphics card. I set that to 50Hz and bingo! Task bar visible again.
Now the mouse works better! So yes, the refresh rate was the main culprit.
Thanks for your help!