All downloads for The Sims 3 at Parsimonious are in a sims3pack file format (for notes on package files see bottom of this page). There are different ways you can install sims3pack files.
This method is easiest for installing lots of sims3pack files at once.
First open the zip you downloaded and then place the sims3pack(s) inside the zip in the following folder:
Next start The Sims 3 Launcher, once it has loaded select the Downloads tab (it should have an ! alert showing there are new items to be installed):
Now check the boxes next to all items you wish to install and click on the 'Install' button at the bottom.
Wait patiently whilst the Launcher installs your items. Hopefully they all install successfully - click Ok to close the installer pop-up. You should now see in the Launcher window that the status of your downloads has changed to Installed.
If you can't find your user folder or only have a few items to install you can do it the slow way.
* note this is quite a good way for first time users to find the correct location of their Downloads folder, since you should now have 2 copies of the file you've just downloaded, by searching your computer for the filename of the sims3pack, the search results should show the temporary folder it is currently in and the Downloads folder that the Launcher has just copied your file to. I suggest adding it to your favourite locations for future use.
Due to a major change in the game that occurred with the Pets Expansion pack, all our objects require EITHER the Pets Expansion pack OR the Pets patch for the base game - patch 1.27 for PC or patch 1.26 for Mac.
This isn't because we messed up our objects or did anything wrong, but this particular game update means that ALL objects made before it no longer work with any game which has Pets or this patch installed, all objects that DO work with Pets/1.27 Patch will not work without it! EA have updated their Store objects, all community creators have to update their objects too if they want them to work with later versions of the game. Thanks EA!
This was written in January 2012 - if when you read this there is a newer patch available then you should get that one instead of any of these please check the Official Site patches link below first:
Before you download any of these patches please read the details on the Official site to find out what this patch does and to check if there is a newer patch available:
Once your game is fully patched and up to date then you should be able to download and use compatible objects as normal, but some older items may not be updated if their creators are no longer around.
What is the difference?"
There is less of a difference than you might think, in fact a sims3pack file IS a package file, just with a bit of extra information for the game that tells it that it is a custom item and what type of item it is.
Many Sims 3 custom content sites only use package files, some will use a mixture or even both types, so if you want to do a lot of shopping for Sims downloads, you'll need to know how to install files that are in just the 'raw' package file.
Since we don't have package files at Parsimonious I recommend reading this guide provided by Sims Wiki which explains the various issues with installing package files. It is not a difficult process BUT there was a significant change with the Ambitions patch (1.12+) that changes WHERE package files should be installed.
Unfortunately there are a lot of problems and bugs with The Sims 3 and methods for creating new custom content are complicated and ever changing. This means many items need to be updated over time and so it is necessary to include some information on how to remove custom conttent files as well as instructions on how to add them. I recommend this Sims Wiki page for details on how to remove sims3pack content: