[other] send (huge) files over Ethernet cable

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http://ubuntuforums.org – I've got an Ubuntu* desktop, a windows XP laptop, a length of Cat5e Ethernet cable (y'know, the one with the squarish plug, usually blue, modern Internet connections use it), and no internet. I've got to transfer a big bunch of files (Most of the laptop's hard drive, more than 50GB) over the cable to the desktop, into a specific directory. Anyone know how to do this? *it dual boots Ubuntu and Windows 7, I can use either here. (Hardware)