Do you have
WinRAR or something similar. If not, you need to download this and put it on the flash drive to install on your computer, or you won't be able to open the files.
Create a new folder on your desktop and download the CC into this folder. Insert the flash drive into the usb port and open it. Click and drag the folder you created with your CC over to the open flash drive window. Remove the flash drive from the usb port and take it to the computer you wish to install the content to. I created a shortcut to my downloads folder and put it on my desktop to make it easy to install cc into my game. You'll find it in documents/EA/Sims2/downloads...if you don't have a downloads folder, create one and make a shortcut to put on your desktop. Open the flashdrive...then open the folder with the CC. Double click on the .rar or .zip files and they should open. Just click and drag the package files to your downloads folder. However, pay attention because if it's packaged with the clean installer, you have to double click the
Clean Installer icon and it will just install to your game (if you drag it to your folder as is, it won't show up). After you install your CC, close the flash drive window, remove the flash drive and start your game. Make sure custom content is enabled or it won't show up in your game...you can enable it in the options section if the custom content screen doesn't show up when you first start your game...I believe it's in game options in the upper right hand corner. After you enable it, exit your game and restart (at least that's what I have to do). Good luck!
Beware of Elves giving wedgies.