Hello, For me, I've started from the TS3, so I don't have many information about the Sims. Last year, my son fell in love with the Sims. I ordered the Sims double deluxe from Amazon for his birthday present. It didn't work on his windows 8.1 OS. Last week, he found the sims complete collection but it doesn't seem to include the sims base game in it. Should he still re install the Sims double deluxe or is there a base game in the complete collection? Will this work in windows 8.1 or will it work in windows 10? I searched everywhere but couldn't get the answer.