Sims 3 Pets Problem...

I have only had the base game and I've wanted Pets for a while, so today I downloaded a Pets torrent. I installed it with no problems up until the point where I copied the TS3W.exe and TSLHost.dll files into the Sims 3 bin...I thought I was supposed to replace the originals with the ones from the torrent, so I did. Ever since, when I try to start the game the launcher won't open, it gave me a popup every time that said it couldn't find the TS3W.exe file, had encountered a problem and needed to close. I downloaded the ultimate fix from here a few minutes ago, and put the TS3W.exe file and TSLHost file back into the Bin, but the game still won't run - when I start it now, nothing happens at all.

If I'm not supposed to replace the original files, am I supposed to leave a copy of each in the Bin?

If it matters, my base game was bought, it's the physical CD, and I want to install Pets, Seasons and Ambitions.

You have to follow every steps of the ultimate fix, and copy/paste files for all expansions that you have.

What you do, is use the manual patch, and just the crack from the fix. Both can be found here.