Updating schema for your forest is not something you do very often, however, it is a requirement when you introduce a Windows server 2003 DC in a Windows 2000 domain or when you introduce the first Windows Server 2008 in your Windows Server 2003 domain. (There may be other times when you have to do this such as when adding Exchange to your environment). Nonetheless it is a very simple and easy task.

 I recently added a Windows Server 2008 domain tree to my existing Windows Server 2003 forest in my lab environment and here is how you do it. You start out by putting Windows Server 2008 DVD (in my case it was mounting the ISO image to the VM) on your schema master DC and from the command prompt you go to the (D:\Sources\adprep\) you can run the help option “/?” to know the syntaxes that apply here.

I ran the “adprep /forestprep”, you will have to hit C and ENTER to give assurance that all your DCs are at Windows 2000 SP4 level or above. In my case it imported about 14 new schema files “.ldf” files and successfully finished.

The next step is to run the “domainprep” syntax from within the same location and that is to be done on your infrastructute master FSMO role. (See FSMO). In my case it was a different DC, so same steps from above except for this time we only had to run the “domainprep” part.

In my case I also ran “adprep /domainprep /gpprep” to update the permissions on my existing GPOs. In future I may write a FAQ or memory refresher about FSMO roles as it is imperative to know the importance of these rules and to understand what we did here and why it could only be done on certain FSMO holders.