First question's going to have to be answered by some more questions - This the product you're talking about? - if it is, what speed is the ethernet connection on the device physically? I can't find anything on WD's specs sheet whether it is 100Mbps or 1000Mbps - is there a GigE switch or a 10/100Mbps switch between your PC and the WD drive? - does Win7 register the NIC speed as 100Mbps or 1000Mbps? - have you benched your NIC and switch with IPERF or similar to see if it can really move a Gigabit of data?
2nd question you're going to have to go to the manual or WD to figure out.