Idiot Alert!!!
 

This borrowed ACER . laptop uses windows 7 but my LG TV ( not a smart TV ) is 2 years old
Right, now for the idiot bit - both have HDMI sockets so IF I connected this laptop to my TV
would anything blow up or would the TV replace the laptops screen? I normally just try things
but as it's SWMBO's machine I thought that I had better ask first :O.

Nervous SLF - The help you need is on the website link below. Depending on the laptop model and its graphic cards processing ability, you may find the laptop has inadequate processing power to produce a full-size picture on the TV screen.

How to plug in your laptop to TV via HDMI cable

Thanks onetrack it actually worked first time which is unusual for me as things don't always :)