How to detect if machine is joined to domain?

Question

How do I detect whether the machine is joined to an Active Directory domain (versus in Workgroup mode)?

Answer 1

Don't fool with pinvoke if you don't have to.

Reference System.DirectoryServices, then call:

System.DirectoryServices.ActiveDirectory.Domain.GetComputerDomain()

Throws an ActiveDirectoryObjectNotFoundException if the machine is not domain-joined. The Domain object that's returned contains the Name property you're looking for.