What sort of IP address conflict is it? I see two different behaviours: one where the PC starts OK, and then pops up to report an IP conflict while it is working, and the other (the converse) where the PC will not start because someone else is already using the IP address.
In the first case, look at the Windows event log of the PC. That will have recorded the conflict, and will tell you the MAC address of the conflicting PC. You can then trace it through the switches, and resolve it.
In the second case, the PC will not come up correctly at all, and you will not be able to ping in or out.
Any half-decent DHCP server will ping the network before it hands out an IP address, to check that it is not already in use. If it does not get a response, it says "OK, here is the address". But,if the address is already in use by a PC that has a firewall on it, then it might not respond to the ping, and you might really have a conflict without knowing it. The only way to resolve this is to look at the conflict in the event log on the PC that is having problems.
Kevin Dorrell
Luxembourg
