Nagwin contains standard Nagios Core and should be able to monitor any device as long as you have monitoring plugins for it. Nagwin has already a small set of plugins ready to use in the /plugins directory, and there are a large number of plugins available at Nagios Exchange. However, due to Nagwin's limited environment and Windows, there may be a limited support. You need to try and find out yourself.
By default, Nagwin is configured to monitor your local machine. See following pages for some basic examples. Nagios configuration files are located at etc\nagios directory. Main configuration file nagios.cfg is configured to accept all configuration files in the subdirectory nagwin. Consult available Nagios documentation to move forward and extend your implementation. Nagwin FAQs available here can also help.
For notification purposes, you can use blat, which is installed as a part of the package (see Nagios.cfg for examples).