1- As everybody else suggested, set a static IP address for the unit.
2- Open notepad and create a batch file as follows:
@echo off
net use z: \\198.69.100.110\Volume_1 /user:ID PASSWORD
To explain the obvious:
- "z:" is the drive letter you want to assign to the NAS. Change it as desired.
- "198.69.100.110" should be the static IP address of the unit in your network. Change it to whatever it really is.
- You can put whatever user name and password you have set for your unit in the command (leave password empty if there is none set).
Once you have edited the command, save it with .bat extension (choose "Save as" other files and put .bat after the name of the file in Notepad)
Double click on the file you created and it will map the network drive to the drive letter you put there. Also drop a copy in your Windows Startup folder so that it automatically run it everytime Windows starts and your drive is mapped and ready to use.
Hope it helps!