here is an in-depth tutorial for rsyncing a windows client to a linux server. It seems to be /cygdrive/c/... not c:\\... though if you're not using the cygwin rsync on windows it may be different.
rsync can't just reach in and grab data from a computer. It won't work unless you're running an rsync server on windows for it to connect to. Here's another set of docs on that.
It's much more straightforward to run the server on linux than windows.