newbie ? about sims & its expansions

[tngoy]

GLH,
That was what I did. I installed The Sims first, played it for a while, got the Hot Date, installed Hot Date. My problem now is that I could not play The Sims any more, only the Hot Date. Each time, I put in The Sims CD and click play, the red Hot Date screen comes up with wrong CD error message. If I put the Hot Date CD in then I could play Hot Date.
In order to play the Sims, I have to install the Sims on another computer.