180GB shouldn't take that long to transfer using LAN (unless you are using 10Mbps cards or an old 10Mbps HUB. You have something set up wrong.
Realistically 180GB shouldn't take more than couple of hours. I say about 3 or 4 hours and no more than 6 MAX if it is taking you days then something is wrong. How old are your PC's? GIve me some specs and how you have them connected.