c# - How to access remote machine to add/remove/manage users accounts?

I have a scenario where I need to access a remote machine to programmatically add and delete Windows users accounts.
The remote machine is a "spare workstation" that I need to remotely configure, to be ready just in case the main workstation need to be replaced - so no security bypass or malicious software here :)

I know user/password of remote machine administrator, and I'm able to retrieve a complete list of existing users account using WMI Win32_UserAccount. Now, I'm trying to obtain an UserPrincipal object for each user (to eventually delete it), but I'm getting exceptions for all of my attempts.

• Attempt #1:

  
  
  

  PrincipalContext context = new PrincipalContext(ContextType.Domain, "xxx.xxx.xxx.xxx" /*remote IP Address*/);
  UserPrincipal user = (UserPrincipal.FindByIdentity(context, "userName"));
  // Do something with user, like user.Delete();
  

  
  
  

  In this case I always get an exception in the first line:

  
  
  

  
  

  System.DirectoryServices.AccountManagement.PrincipalServerDownException
  was caught Message=The server could not be contacted.
  Source=System.DirectoryServices.AccountManagement StackTrace:
  in System.DirectoryServices.AccountManagement.PrincipalContext.ReadServerConfig(String
  serverName, ServerProperties& properties)
  in System.DirectoryServices.AccountManagement.PrincipalContext.DoServerVerifyAndPropRetrieval()
  in System.DirectoryServices.AccountManagement.PrincipalContext..ctor(ContextType
  contextType, String name, String container, ContextOptions options,
  String userName, String password)
  in System.DirectoryServices.AccountManagement.PrincipalContext..ctor(ContextType
  contextType, String name, String container, String userName, String
  password) InnerException:
  System.DirectoryServices.Protocols.LdapException
  Message=The LDAP server is unavailable.
  Source=System.DirectoryServices.Protocols
  ErrorCode=81
  StackTrace:
  in System.DirectoryServices.Protocols.LdapConnection.Connect()
  in System.DirectoryServices.Protocols.LdapConnection.SendRequestHelper(DirectoryRequest
  request, Int32& messageID)
  in System.DirectoryServices.Protocols.LdapConnection.SendRequest(DirectoryRequest
  request, TimeSpan requestTimeout)
  in System.DirectoryServices.Protocols.LdapConnection.SendRequest(DirectoryRequest
  request)
  in System.DirectoryServices.AccountManagement.PrincipalContext.ReadServerConfig(String
  serverName, ServerProperties& properties)
  InnerException:

  
  




• Attempt #2:

  
  
  

  PrincipalContext context = new PrincipalContext(ContextType.Machine, "xxx.xxx.xxx.xxx" /*remote IP Address*/);
  UserPrincipal user = (UserPrincipal.FindByIdentity(context, "userName"));
  // Do something with user, like user.Delete();
  

  
  
  

  In this case I always get an exception in the second line:

  
  
  

  
  

  System.IO.FileNotFoundException was caught Message=Network path not
  found.

  
  
  

  Source=Active Directory StackTrace:
  in System.DirectoryServices.Interop.UnsafeNativeMethods.IAds.GetInfo()
  in System.DirectoryServices.DirectoryEntry.RefreshCache()
  in System.DirectoryServices.AccountManagement.PrincipalContext.DoMachineInit()
  in System.DirectoryServices.AccountManagement.PrincipalContext.Initialize()
  in System.DirectoryServices.AccountManagement.PrincipalContext.get_QueryCtx()
  in System.DirectoryServices.AccountManagement.Principal.FindByIdentityWithTypeHelper(PrincipalContext
  context, Type principalType, Nullable`1 identityType, String
  identityValue, DateTime refDate)
  in System.DirectoryServices.AccountManagement.Principal.FindByIdentityWithType(PrincipalContext
  context, Type principalType, String identityValue)
  in System.DirectoryServices.AccountManagement.UserPrincipal.FindByIdentity(PrincipalContext
  context, String identityValue)
  InnerException:

  
  

I've tried different signatures of PrincipalContext object (with domain name instead of IP address, with user name and password, ...) but I always get exceptions on both attempts.

Am I missing some instructions? Do I need to use impersonation to gain full acces to remote machine before to create PrincipalContext object?
Any other ways to accomplish what I'am trying to do? (that is, access a remote machine to add/remove Windows account)

Answer

If you simply want to remove the account, why not use Directory Services instead:

using System.DirectoryServices;

DirectoryEntry deParent = new DirectoryEntry("WinNT://[computername]", 
         @"[domain\adminname", "password");            
DirectoryEntry deToRemove = deParent.Children.Find("usernametoremove");
deParent.Children.Remove(deToRemove);