@igazor Thank you so much for your kind help. As you say, I'm going to wait and see how it goes but in the meantime I will uninstall TS3 from my Mac side as I never play it there, I have The Sims 2 Super Collection to play on the Mac.
I had my very old iMac OS changed just a year ago, to High Sierra before that, I think it was Leopard (this Mac is from 2010 nearly as old as me! :D So I should be all right with the OS. It has 16 Gb memory but it uses 8 Gb on each side (that might be a problem?)
Otherwise it's a great computer and the partition is Windows 7 which is useful to have for some older games.
I will find all relevant technical info and will post it for you.
