1) Change the servers address to the proper network. ie: 192.168.10.10
2) In DHCP manager de-activate the current scope
3) Create a new scope with the range 192.168.10.1 to 192.168.10.254
4) Exclude enough to take care of all static addresses ie: exclude 192.168.10.1 to 192.168.10.49 (allowing 49 statics)
5) Setup scope parameters for router (gateway address) DNS (server dns) and Wins (number 44 and 46) Make sure to setup addresses on each parameter. The Wins server should be the server IP address and the Node type should likely be 0x8.
6) If you changed the server's ip address make sure that you change the server's Wins server address to the same number also.
7) Activate the scope and login from a workstation.Do an ipconfig from Windows 2000/NT workstations or winipcfg from Win9x machines to determine if they are receiving proper addresses from the DHCP server.
8) If this is not enough detail, please respond with specific questions. You may reboot the server just to make sure everything is restarted. Beyond this if DHCP is not handing out addresses MAKE SURE there are no other DHCP servers on the network. This may become apparent when you do IP Config or Winipcfg. There have been a couple of instances when I have had to reinstall DHCP to get it to work but only as a last resort.
This is a decent start. Good Luck!