Thankyou, there were no unzip options when I right clicked so I assumed all OK just to open which I did and then copied the file you said into my username/gimp.2.8. I then opened gimp but am unsure how to edit gimp preferences? I clicked on edit (in gimp) and then preferences but there was nothing in there that said plug ins so don't know how to do the next step of point to plug ins - I'm very grateful for some more tips! I'll get there in the end!

after having selected Preferences, click on the small triangle which says Folders, inside there is Plug-ins, select it, click on the white small document icon on the top left to request add, then click on the right folder icon to browse your folders, choose the one where gmic is then press OK

i attach here the panel set for adding a folder in the plug-ins folders for gimp
(note: you don't see here gmic, because i'm not correctly on a win 64bits PC, but you see the panel sequence, on the top right one you have to do your choice)

Well I'm slowly getting there but not quite! So I followed those instructions and GMIC now is in the list of filters - however where as all the other filters are in black and can be clicked on, the GMIC one is written in grey and nothing happens if you click on it!

After typing the above I suddenly thought I'll try and open gimp from one of my saved photos. When I do that GMIC is there - so I thought yipeeee all sorted but then within a couple of minutes gimp stopped responding and I got a message saying:
Plug in crashed
The dying plug in may have messed up GIMPs internal state. You may want to save your images and restart gimp to be on the safe side.

I've restarted it and when there is a photo there GMIC is there to be used - but unsure if it will keep crashing until I test it more! My laptop is off for some repair work tomorrow so don't know how long I'll be without it but will try to use the GMIC filter afterwards again. Thank you so much for the help - at least GMIC is there now but don't know if you have any tips to stop it crashing!

you are really unlucky, my dear Lucy
let's see in a few days what happens

Maybe my laptop will get used to it! It will probably be a little while now until I attempt to improve my photo again but will let you know how I get on - I had been happy with the improvements but now I'm not so sure and want more - so hoping GMIC will give me that - although I might end up having to post on how to use it!

Lucy,
when you will come back to Gimp and Gmic, may I suggest you to restart with a "clean" environment, that is:
1-uninstall gimp
2-save somewhere (unless you want to redownload it) samj' gmic plugin folder
3-remove (delete) both gimp folders: the one under Programs and the one under your-user-name/
4-redownload gimp from source-forge and reinstall it
5-redo the steps to link the gmic plugin folder under preferences
Maybe the environment is no more totally clean, due to the many trials.
Don't discourage, it is more or less a common practice to reinstall gimp!...

Ok thank you dinasset - I really appreciate the advice!