C#: How would you organize a screen saver in the file system?

Question

I am planning to create a screen saver. Thinking of trying out some WPF as well. Anyways, I am not quite sure how I would organize the screen saver on disk in the file system. I have mainly two related issues that I am very uncertain on how to solve:

1. Normally an application lives, with all its 3rd party assemblies, static resources, images, etc., in the Program Files folder and is run from there. For example C:\Program Files\MyScreenSaver. But (if I haven't missed something) the executable of a screen saver in windows need to have the scr extension and to live in the system folder, for example C:\Windows\System32. How do you program the screen saver so that it can find the "rest of itself"? Would you use the windows registry? Or creat some sort of config file next to the scr file with the path to the rest? And would you make the scr to just be sort of a launcher of an exe in the application folder? Or would this be a bad idea?

2. I also want the screen saver to download new content from certain places on the internet. But where do I put it, and how does the screen saver find it? If I have understood correctly, an application is not to create new contents in its application folder, but rather in a user folder. How do I find that folder? Do you build it up from environment variables? And in what specific directory should things like this really be in? For example on Vista I see that you have one folder called C:\ProgramData. You also have C:\Users\username\AppData\Local, C:\Users\username\AppData\LocalLow and C:\Users\username\AppData\Roaming. Have also seen a lot of programs dump stuff in the my documents folder (although I hate programs cluttering up my documents folder, so I will probably try to avoid that :p).

What are some best practices when it comes to these issues of laying out your application in the file system? I am want it to be best and "most correct" for Windows 7, which means it will probably work the same in Vista as well (?), but it would also need to work in XP, since a lot of people are using that still.

Answer 1

I'm still using XP :)

System.Environment.SpecialFolders is what you want for these special locations.

Say,

System.Environment.SpecialFolder.LocalApplicationData

Answer 2

For a screen saver I'd try to put most of it in the .exe (.scr) file. It might make the executable quite big but I think it's worth it.

For the downloaded content use application data folder, or maybe allow user to set the location (put the path in registry). For example if you are downloading images, the user might want to put that in My Pictures folder.