Can't see NAS

[Rowan]

I have a Zyxel NAS connected via Ethernet to my network, to which my PCs are also connected via WiFi and a couple of access points. If I go to Windows Explorer on either my Windows 8.1 desktop or my Windows 10 tablet, I can't see the NAS (which is called NSA310). If I look in my router, I can see its MAC address, and hence discover its IP, which is 192.168.0.68. If on the PC I ping 192.168.0.68, it works fine. If I do ping nsa310, it says "Ping request could not find host nsa310. Please check the name and try again.". If I do nslookup 192.168.0.68, it says:
Server: www.routerlogin.com
Address: 192.168.0.1

*** No internal type for both IPv4 and IPv6 Addresses (A+AAAA) records available
for 192.168.0.68

If I do nbtstat -A 192.168.0.68, it says:
Ethernet:
Node IpAddress: [0.0.0.0] Scope Id: []

Host not found.

Bluetooth Network Connection:
Node IpAddress: [0.0.0.0] Scope Id: []

Host not found.

Wi-Fi:
Node IpAddress: [192.168.0.76] Scope Id: []

Can anyone suggest what may be wrong, and how to get this NAS so I can actually use it?

Thanks - Rowan

 

[Trouble]

IF you right click the start button and choose "Run" from the context menu and in the Run dialog box you type
\\192.168.0.68
and hit enter or click OK....... what happens?