EDIT: rsync: failed to connect to 192.168.0.100: Connection refused

This means your PC is not listening on rsync's tcp port, ie rsync is not running. You can test whether your PC is listening by typing "rsync 192.168.0.100::" from the empeg command prompt, or by typing "rsync localhost::" in the cygwin bash shell. It would then show the rsync modules you have configured in /etc/rsyncd.conf.

If I try to start the service, it will start and then stop, because windows says it has nothing to do

This means there's something not set up right in your cygwin environment. Check whether rsync is really installed at all, whether cygrunsrv is installed, check /etc/rsyncd.conf (whether it's there, whether it contains the right syntax and whether it does not contain carriage returns). You can add
"log file = /unix/path/to/a/logfile" to /etc/rsyncd.conf to see what is happening. You could also type "rsync --daemon --no-detach" from the command line rather than as a service to see whether it can find the rsyncd.conf file at all.

Pim