For some reason I cannot edit the question and make corrections in my original post so I am re-posting the edited question here:

Say there are 2 games: 'A' and 'B' and there is another game 'C' which is a stand alone expansion to the games 'A' and 'B'. It says in the description box of the game 'C' that if you have the games 'A' and 'B' already installed then you can play the game 'C' with new and added features.

If I buy the game 'C' first without buying the games 'A' and 'B' and install and start playing the game 'C' and then after a few days buy the games 'A' and 'B' and install them, would I still be able to play the game 'C' with those new and added features.............or do I have to first uninstall 'C' then install 'A' and 'B' and then reinstall 'C'?

Say there are 2 games: 'A' and 'B' and there is another game 'C' which is a stand alone expansion to the games 'A' and 'B'. It says in the description box of the game 'C' that if you have both the games 'A' and 'B' already installed then you can play the game 'C' with new and advanced features.

If I buy the game 'C' first without buying the games 'A' and 'B' and install and start playing the game 'C' and then after a few days buy the games 'A' and 'B' and install them, would I be able to play the game 'C' with those new and advanced features.............or do I have to first uninstall 'C' then install 'A' and 'B' and then reinstall 'C'?