If there is not a FireWire port on the Windows host computer, you will need to purchase an adapter for the system. Target disk mode requires the host computer (systems accessing the Mac) to connect via a FireWire port (or Thunderbolt with newer Macs) to the target Mac. On each Mac, choose Apple menu > System Preferences, click Sharing, then note the computer name for each computer. You don’t need to use an Ethernet crossover cable. You can use an Ethernet cable to connect two Mac computers to share files or play network games. When a Mac is booted in target disk mode, the typical boot sequence is bypassed and the operating system is not loaded. Target disk mode is a way of booting a Macintosh computer so that it acts as an external hard drive on another computer.
Before performing the migration, use Software Update on your older Mac to ensure you get the latest updates for Mac OS X. To use Migration Assistant, both Macs must be either Firewire / Thunderbolt capable or be connected to the same Ethernet cable or wireless network.
MIGRATION ASSISTANT PC TO MAC VIA ETHERNET CABLE HOW TO