If You have previously installed Windows 98 SE Internet shared connection it could be the problem, the machine tha was running shared connection acts as an dhcp server and generates conflicts with e-smith's dhcp own server.
possible solution
remove shared internet connection component from windows setup
remove any other program acting as gateway or look for modificatios that programs could have done
run winipcfg to check the status of the ip assignments and dhcp service.
the last, as always: do a start from scratch "fresh install the windows machine"
This is not an act of knowledge, but it surelly works!
regards,
Alejandro