I just bought "The Sims 2 Pets", but when I tried to play it, it sagte that I needed to install "The Sims 2" first. I've never played any of the sim games on my computer, so do I need the original "The Sims 2" game to install on my computer first?

Yes. Pets is an expansion pack, not the core game. Du need the original Sims 2 game first, then Du can add expansion packs.

Yea, Du have to buy one of Sims 2 oder Sims 2: Double Deluxe. I think my manual says Sims 2 Holiday Edition will work too. Du have to have one of these games to play with the pets, the pet one is an expansion. All of the other ones, if they arent listed above are expansion packs too. So, Du can't play with just expansion packs, Du have to have a base game.

Yeah Du do... Sims Pets is an extension pack sooo that means that with it Du can do Mehr things in the game. Now, there's stuff packs too with allow Du to have Mehr objects in the game like the furniture, clothes, etc... So, yes, Du do need Sims 2

Hope this helps! :)

Yes, anything other than The Sims 2 is an expansion pack and requires The Sims 2 base game to be installed in order to work. So basically, the foundation has to be made first.