I'm an IIS beginner so please be kind.
The packages files (exes) are not downloading from the IIS web server from client machines. You can browse into maps and packages, but when you click the exe file and nothing happens. If you visit the site using a browser on the server itself, it downloads. Does that imply its an issue with NTFS permissions?
Using a share rather than IIS allows clients to run the file. I am thinking permissions but I guess it could be IIS configuration, but its just the vanilla install so I expected it to work!