Upgrading Domain from 2000 SP4 to 2003 R2

Hi guys,

I am planning to upgrade our 2000 domain to 2003 R2. I run addprep/forestprep and /domain prep from
2003 R2 first CD. Recently I read in net I need to do that from second CD is it true? I didnt add 2003 R2 domain controller to domain yet, Am I need to rerun those commands from second CD before adding 2003 R2 domain controller to existing(2000) domain?

Thanks
Sridhar.