active directory switch to native mode

As long as you have a mix of Windows 2000 and Windows 2003 DCs in one domain, you cannot put your domain into native mode for either Win2K or Win2K3. Also, if you have updated your active directory with any Windows 2003 information, you can't go into native mode for Windows 2000. However, if the other non-Windows 2000 servers in your domain are NOT domain controllers, AND if you have not actually run forestprep and domainprep for Windows 2003, then you can put your domain into Windows 2000 native mode. This is done simply by opening AD Users and Computers, expand so that you can see your domain name, right click on the domain and click "Raise Domain Functional Level."

Hope this helps!

I don't agree with the previous post.

With 1 W2K and 3 W2K3 DC's you can move your domain to W2K Native.

You cannot however switch to Windows 2003 Interim or Windows 2003 functional level

check this article:
http://technet2.microsoft.com/WindowsServer/en/library/b3674c9b-fab9-4c1e-a8f6-7871264712711033.mspx?mfr=true