forest and domain functional levels 2008 r2 upgrade

**Breckon** · 22-09-2009

I am currently testing the newly added Windows 2008 domain controller to a Windows 2003 domain that also has 2 Windows 2003 DCs. I did run the forest prep and domain prep properly but checked that the forest functional level for the domain is set to Windows 2000 functional level. Will I be able to raise this to Windows 2003 functional level without any problem now or is it something I should have done before updating the schema to 2008 r2? Thanks

**Janos™** · 22-09-2009

Yes, you can easily raise it without any problems.

**Big Fish** · 22-09-2009

I think that you need to ensure that you dont have any NT4 or Windows 2000 DC's in your environment. Once it is raised you wont be able to go backwards and you will lose access to those older DCs.

**ApPy10** · 15-10-2009

Even I agree that you have to make sure about the older OS version on DCs. You can also check the below link if you plan to go on the 2008 or 2008 R@ levels:
http://technet.microsoft.com/en-us/l...32(WS.10).aspx