A. Domain and forest modes are defined by a combination of three values: For the domain mode, you need to check the msDS-Behavior-Version and nTMixedDomain attributes of the Domain container; for the forest mode, you check the msDS-Behavior-Version attribute of the Partitions container, which you'll find in the Configuration object of the Forest root. To view these attributes perform these steps:

1. Start ADSI Edit (Start, Run, adsiedit.msc). This tool is part of the Windows 2000 and later Support Tools so make sure you have these tools installed.
2. Expand the Domain branch. Right-click the domain name and select Properties from the context menu. (If the domain you want isn't displayed, select "Connect to..." from the root context menu and enter the domain information, including credentials for a connection.)
3. Click the Attribute Editor tab and scroll down to view the msDS-Behavior-Version and nTMixedDom values. These are the domain-specific values.
4. Expand the Configuration object at the root of adsiedit and expand the Configuration container specific to your forest. Right-click the CN=Partitions container and select Properties.
5. Click the Attribute Editor tab to view the msDS-Behavior-Version value, as the figure shows. Click OK.
6. Close ADSI Edit.