Stage One of Migration to Exchange 2007

As per plan I started with upgrading all Domain Controllers to Windows 2003.
Stage I
Bfore we start anything with Active Directory Backup.. Backup... Backup.... Especially the System State Data

Make existing Win2K ADS scheme to be modifiable using Schema Management Console from using mmc. If you are not able to see the snap in then pls register the Schema Management Console with MMC using the following command in system32 folder

C:\WINNT\system32>regsvr32 schmmgmt.dll

in Active Directory Schema console right click on Active Directory Schema and Choose Operations Master. In the Choose Operations Master windows select the option "The Schema may be modified in on this Domain Controller"

Ok thats it!
Now the schema is ready to be modified but running forestprep and adprep using Win2K3 CDROM now is dangerous as it can lead to some of the LDAP entries to be mangled as the result of it. So be careful not to run forestprep or adprep now

This issue is briefly discussed by Microsoft here
So this issue need to be tackled first running a small ready made script from Microsoft. Pls copy and paste it on notepad. Take the script from the microsoft site

But bfore we start we need to make small schema change to able to handle the existing Win2K domain to smoothly handle moving to Windows 2003 ADS. This is achieved by running a script file on the mail domain Controller(FSMO)

Run the script by
ldifde -i -f inetorgpersonprevent.ldf -v -c DC=X "dc=yourdomain,dc=com"
Pls replace yourdomain and com with appropriate entries for your scenario

Once you do this give enough time for the Replication to take place. Reboot the domain controllers to make sure the changes propagates though the entire domain
Give one or two days rest time to make sure everything is working fine and nothing broken