How do I remove an old NAS/FIle Server?
The contents of the "Network" location is not something stored on your computer that you can delete. Instead it shows the current state of your network.

This means that you have a device that broadcasts its presence to the network letting you know that it is named DJM-NAS-1 via NetBIOS. You can get rid of it here by stopping that announcement on the NAS unit - and this is also where you can change the name of it. The icon is determined by the type of software used on the NAS unit.