Is there any API or tool that can automate software updating? It should take care of checking for updates from a URL for a provided list of files and downloading and replacing the ones that need updating. It would also be nice if it contained an authentication module so that only authorized parties could access the updates. It should be language-agnostic - takes a list of files without extra knowledge except their versions and replaces them with newly downloaded copies if on the site there are newer versions.
I'm specifically interested in something for the Windows platform, that would run on Win Xp to Win 7.