To anyone else who wants to reset Sims 2 (disk version, Sims 2 Ultimate Collection) to a vanilla state (which means no saved games, CC or Mods present), here are instructions on how to do so. First locate your Sims 2 folder which is found Documents > EA Games > Sims 2. For some of you, you will see two folders. One will be "EA Games" the second one "Electronic Arts". The "Electronic Arts" folder houses similar folders, but is only used for the following games: Sims 3, Sims 4 and Sims Medieval. "EA Games" houses the Sims 2 folder. Move the Sims 2 folder to your Desktop for safe keeping. Do not copy and paste or create a shortcut, actually move the folder to your Desktop. If you have successfully played Sims 2 previously and are encountering problems recently, this is a good way to troubleshoot and reset your game without losing progress. Your saved games, CC and Mods will be safe on your Desktop. Next, start up the game to allow for a new Sims 2 folder to generate. Start up a new game and play for about an hour to make sure the game is running ok and you are not encountering the errors you may have previously seen. You can either save the game or simply quit. At this point, you can transfer back your CC, mods and saved games back into the new folder that the game just created.
For Aspyr's version of Sims 2 Super Collection (for the Mac OS), your location of the Sims 2 folder is in a different place. Make sure your header at the top is on Finder and locate the "Go" tab at the top. Press the Option key to show the hidden folder "Library" which is where your Sims 2 folder is. Scroll through the folders until you find "com.aspyr.sims2.appstore", open that up and open the Data folder. Under that file, open the Library folder and open the Application Support folder. In that folder, you will find one more folder named simply "Aspyr" and that is where the Sims 2 folder is located. Follow the steps above and move that folder to your Desktop and continue with the steps listed above.