The fact you can still access the NAS via the web interface points to a possible problem with your windows network setup.
Can you see Volume_1 if you open windows explorer, network, DLINK-xxxxxx (where xxxxxx is some hex number)? If so you then need to remap your drives.
If you don't see Volume_1 then you should check that the NAS and your PC are using the same workgroup (not workgroup on the NAS and homegroup on the PC)
Sorry I can't be more helpful but I only see windows when friends and the odd client ask for help.