[cody]

Network the computers together using a crossover cable or by connecting them both to the same switch or a router. Let's assume one is XP and one is Vista. Change the workgroup name on the XP machine to be the same as the Vista machine, if it isn't already (Right click My Computer>Properties>Computer Name Tab>Change Button). Reboot the XP computer if you had to change the Workgroup Name (you'll be prompted to reboot after changing it).

Open My Network Places. Wait up to an hour for the other machine to show up and then double click it (or Run> "\\[IP Address of other computer]" (without quotes) if you know it (You can look it up with Run>"cmd">ipconfig)). Enter username and password if prompted. In the address bar of Explorer, add "\c$" to the end of the machine name. Enter username and password if prompted. An Explorer window to the Vista machine's C drive will open. Then push the old files to the new machine via drag and drop. Windows will copy the files to the new machine.

If you have issues, make sure the two machines have the same time within a minute or they won't "see" eachother. Also make sure Printer and File Sharing is turned on and not being blocked by any software firewall.