How to using BT3 to crack(obtain) windows xp administrator account on network?

1. Now in my network having 5 pc, let's say i want to crack(obtain) one of windowsXP administrator account password via network, BT3 have a tools to do it? or any method to do it? i just know using the Ophcrack live cd to crack windowsXP administrator password in local pc, not via network, how to do it via network?

Thank you.