Hello,
In which folder do I put the buildings {the mods}???
And the Fireworks, and the rest

: (: (-Jarno

it should have a 'read me' file with the set, read that and it will tell you where to install. if there is no 'read me' file, just stick it in style/themed and it should work

My system might be a little different...but if what SUPER MOOSE93'S suggestion doesn't work (all though I've gotten great help from him) here is what I would try next...

If you are talking about mods (models, fireworks and other scenery, structures) downloaded from this site....

In my documents folder (different from the hard drive) there is an RCT3 Folder and in that folder are subfolders structures (for buildings), fireworks, coasters (tracks), etc. With these this is how I was able to get them into the game without it crashing, most of the time. If you are talking about custom scenery items...Then I go to (my hard drive programs x86) Atari, Style (usually near the bottom), themed. This has worked for me when i was using windows 7 and now i am using windows 8.1 and the game and custom scenery works fine.

Sometimes there is a download limit...I posted in a previous post in the "All That" forum on how to change the number of downloads in google chrome. here is the link http://forums.rctgo.com/thread-18517.html