Simon,
There are a couple of ways to do this.
1. You can use the Active Directory Migration Tool to migrate all of your
users and group automatically. It is a free download at Microsoft.com.
Make sure you get version 2 if you decide to go this route. The process is
fairly involved, but you have the most options if you use this utility.
http://support.microsoft.com/?id=325851
2. You can use the addusers utility from the Windows 2000 resource kit to
dump all of your users and groups to a text file and then you can use
addusers to import all of your users and group to your new domain.
http://support.microsoft.com/?id=199878
There are some limitations with using addusers vs ADMT. ADMT is more
powerful so it will allow you to migrate SIDs, profiles and passwords where
as addusers essentially creates new users in the new domain with brand new
sids and no passwords. Addusers also does not allow you to migrate
profiles, though you can do this manually through the registry if you do not
have too many users.
I hope this helps.
Ray Lava
Microsoft Corporation
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