Are you making sure it is in the correct EA folder? As said above Windows 7 makes two folders, one the game uses and a useless one.
is your Download folder spelt with a capital D
If the above doesn't help can you tell us step by step what you are doing to put the cc into your game and link us to something else you might use?

I would never just tip things into your download folder. Sub folders came available a very long time ago and should have no effect on your game unless you are using too long file names or going too deeply. A few things sometimes don't show in sub folders like baby clothes, but normally things can be sub foldered.

I think it might have been the sub folders. I just pasted and dumped everything into the Downloads folders. I'll try again and see if taking them out the sub folders works.
I also had all the meshs for everything. I'm going to try a coupled more times and see if anything helps.

I just got them to work! It was a matter of placing them into the correct folder and not putting them in sub folders. Thank you all for helping. Also i'd like to point out that in the ultimate collection (I noticed this on the instructions) that you go to C:\Program Files (x86)\Origin Games\The Sims 2 Ultimate Collection\Fun with Pets\SP9\TSData\Res\Catalog\Bins and then everything works. Downloads folder isn't needed.