In order to determine the hostname of your computer, follow the instructions for your operating system below: 

MacOSX, Linux (all flavours): 

• Open a terminal window (in the other folder in MacOSX, in the file menu on KDE etc)
• Then type "hostname" without the quotes. This will give the machine hostname. 

Windows 7/8/10:

• Open a command prompt (in accessories in 7, under windows system in 8 and 10)
• Then type "hostname" without the quotes. This will give the machines hostname.