theres several ways to do it.
if the drive is still in the laptop you can link the laptop directly to the PC via the ethernet jacks (assuming you have a NIC-network interface card) just conenct them with a peice of crossover cable and run the networking wizard (assuming XP on one of the boxes)
you can get an external HD case, that will let you do a USB/Firewire/Ethernet (one of the above, or sometimes 2) connection into any PC with any of those ports. (2.5" laptop drives usually get power from USB)
also I belive there are adapters that conver the pin on back of 2.5 drive to USB, search laptop HD 2.5 to USB converter in google or newegg.
hope one of these options is helpful
let me know if you need more info (though I've never used the 3rd option)