HOW

[Toyah Halostar]

I may be being thick BUT 

I loaded the software 

It shows an IP on my router 

I have tried every way I can think of but cannot open the NAS at all 

[Sonuinrbrqes]

I'll caveot - my d-link is 2000 miles away from my and I cannot give you setup specifics.  I assume you mean by 'cannot open' that you are connecting a windows PC to the NAS and it won't connect?  But you should still be able to access the web console via the IP address you have, by browser, and perform setup functions.  So this is Linux and to connect Windows, you need a folder structure setup with appropriate read/write access where you plan to store your files and you can do this via the web interface.  Next, if you want to network with windows, you also have to load/install the Samba SMB and also configure it to point to the folder you setup for your files.  You can find that in the tools or setup part of the web interface and install/configure.   I referenced the alt-f how-to guide to configure the apps and network interfaces.