Verifying Functional Levels by Using ADSIEdit

To determine the domain functional level, Windows Server 2003 uses a combination of two attributes stored in Active Directory. To determine the forest functional level, Windows Server 2003 uses a single attribute.

To verify the forest and domain functional level by using ADSIEdit.msc:

1. Open a Run command, and type ADSIEdit.msc
2. Expand the Domain object, right-click domainname (where domainname is the distinguished name of the domain that you want to check), and then click Properties.
3. Under the Attribute column, scroll until you locate the msDS-Behavior-Version attribute. Check the value of this attribute.
4. Check the value of the nTMixedDomain attribute on the domain object. The following table provides the details for both attributes for the domain functional level.

1. To verify the forest functional level, expand the Configuration object, and then expand the CN=Configuration,forestname object (where forestname is the distinguished name of the forest).
2. Right-click the Partitions container, and then click Properties. Locate the msDS-Behavior-Version attribute, and check the value of this attribute. The following table provides the details for the attribute for the forest functional level.

Source: Microsoft Corporation