Help!!!!!

I have several (erm about 100+) windows 2000 professional clients who are configured for DHCP, but none of these clients can get an IP. The server is windows 2000 server and is running perfectly (another 90 odd clients are connecting with no problems using Windows 9x).

I have AD and DNS installed and are working perfectly. AD and DNS are on the same server, DHCP is on a different server.

If I watch the DHCP statistics while trying to connect from a Windows 2000 pro client then it can see the client trying to connect (Request).

There are about 200 ip addresses available but only about 50 have been taken (by Windows 9x).

It works if I have reserved a Windows 2k pro client by their MAC address, but I couldn't do this for all my 2k pro clients.

Anyone!!!!!!!