On Windows systems, make the following steps:
> getmac /v /fo list
Look for a string like "Physical Address: E0-58-06-42-0E-B4" in your connection information (if you have multiple connections configured, the one you need is named "Local Area Connection" by default). Remove the field name and dashes to form a host ID like this: E05806420EB4, and copy it to the Host ID form field.
On most Linux systems, host ID is the MAC address of the eth0 interface.
Use the following command: $ ifconfig eth0
Look for a string like "HWaddr e0:58:06:42:0e:b4" in the first line of the output. Remove the field name and colons to form a host ID like this: e05806420eb4, and copy it to the Host ID form field.