Are you on .NET 3.5? If so, check out this MSDN article: Managing Directory Security Principles in the .NET Framework 3.5 .
CodeProject: Howto: () Active Directory #
System.DirectoryServices MSDN.
Active Directory # VB.NET, :
.NET

" " ( : DisplayName) , ( .NET 3.5):
PrincipalContext ctx = new PrincipalContext(ContextType.Domain, "yourDomain");
UserPrincipal up = UserPrincipal.FindByIdentity(ctx, "(your user name)");
if (up != null)
{
up.DisplayName = "new display name for your user";
up.Save();
}
! :-)
: NetBIOS (, "MICROSOFT"), DNS (microsoft.com) PrincipalContext.
!
.NET 2.0:
, .NET 2.0 "displayName" , "SAMAccountName" ( ):
DirectoryEntry root = new DirectoryEntry("LDAP://dc=yourcompany,dc=com");
DirectorySearcher ds = new DirectorySearcher(root);
ds.SearchScope = SearchScope.Subtree;
ds.Filter = string.Format("(&(sAMAccountName={0})(objectCategory=Person))", yourUserName);
SearchResult result = ds.FindOne();
if (result != null)
{
DirectoryEntry userEntry = result.GetDirectoryEntry();
userEntry.Properties["displayName"].Value = yourNewUserFullName;
userEntry.CommitChanges();
}