While doing system troubleshooting I will sometimes come across an IP address which is causing some issue and is getting reported on an error log.  It could be a server, or a network user, and it would be helpful to know the Hostname in order to dig in further.

CMD

The easiest method that I have come across is to use the windows command prompt.

• Start > Run > CMD
• ping -a [IP ADDRESS}

There are other methods such as using power shell, java, C#, etc, but if you are not trying to integrate this hostname into some other commands then CMD should be all you need.