Step1: Unlock all hidden folders. You can unlock the hidden folders by doing the following. This is for Windows users only.
To display hidden files and folders
Open Folder Options in Control Panel.
Click Start, and then click Control Panel.
Click Appearance and Themes, and then click Folder Options.
On the View tab, under Hidden files and folders, click Show hidden files and folders.
Notes
Hidden files and folders will appear dimmed to indicate they are not typical items. Usually, hidden files are program or system files that should not be deleted or changed. To display other hidden files, clear the Hide protected operating system files (Recommended) check box.
If you know the name of a hidden file or folder, you can search for it. For more information, click Related Topics.
If you want to see all file name extensions, clear the Hide file extensions for known file types check box.
Step2: Follow this path through your computer.
C:\Documents and Settings\All Users\Application Data\Microsoft Games\Zoo Tycoon 2\downloads\zootycoon_com_zt2_1033
Step3: Inside this folder is where you put all of the .dl files. There should already be some if you have any of the official downloads. A .dl file makes the creation that you have downloaded appear as a download in the game.
Step4: Also inside the 1033 folder should be some folders with numbers such as 1016. You should put the .z2f files in one of these folders. If you don't have these folders, that is because you have no official downloads.
This is for making the downloads work in the game.