C# – Change Service Account Username and Password

Change Service Account Information using Win32 API

Use the below C# sample code to update service account username and password. It uses the Win32 API function ChangeServiceConfig. The ChangeServiceConfig function changes the configuration information for the specified service in the service control manager database.

private const int SC_MANAGER_ALL_ACCESS = 0x000F003F;
private const uint SERVICE_NO_CHANGE = 0xffffffff; //this value is found in winsvc.h
private const uint SERVICE_QUERY_CONFIG = 0x00000001;
private const uint SERVICE_CHANGE_CONFIG = 0x00000002;

[DllImport("advapi32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern Boolean ChangeServiceConfig(IntPtr hService, UInt32 nServiceType, 
    UInt32 nStartType,UInt32 nErrorControl,String lpBinaryPathName,String lpLoadOrderGroup,
    IntPtr lpdwTagId, [In] char[] lpDependencies, String lpServiceStartName, 
    String lpPassword, String lpDisplayName);

[DllImport("advapi32.dll", SetLastError = true, CharSet = CharSet.Auto)]
static extern IntPtr OpenService(IntPtr hSCManager, string lpServiceName, 
     uint dwDesiredAccess);

[DllImport("advapi32.dll", EntryPoint = "OpenSCManagerW", ExactSpelling = true, 
    CharSet = CharSet.Unicode, SetLastError = true)]
public static extern IntPtr OpenSCManager(string machineName, string databaseName, 
     uint dwAccess);

public static bool ChangeServiceAccountInfo(string serviceName, string username,
       string password)
{
    try
    {
        IntPtr scm_Handle = OpenSCManager(null, null, SC_MANAGER_ALL_ACCESS);
        if (scm_Handle == IntPtr.Zero)
          throw new System.Runtime.InteropServices.ExternalException(
                      "Open Service Manager Error");

        IntPtr service_Handle = OpenService(scm_Handle, serviceName,
                                        SERVICE_QUERY_CONFIG | SERVICE_CHANGE_CONFIG);
        if (service_Handle == IntPtr.Zero)
          throw new System.Runtime.InteropServices.ExternalException("Open Service Error");
        //Changing the user account and password for the service.
        if (!ChangeServiceConfig(service_Handle, SERVICE_NO_CHANGE, SERVICE_NO_CHANGE, 
             SERVICE_NO_CHANGE, null, null,IntPtr.Zero, null, username, password, null))
        {
            int nError = Marshal.GetLastWin32Error();
            Win32Exception win32Exception = new Win32Exception(nError);
            throw new System.Runtime.InteropServices.ExternalException("Could not change 
          user account and password : " + win32Exception.Message);
        }
        Console.WriteLine("Service account information changed successfully");
        return true;
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.ToString());
        return false;
    }
}

Change Service Login Username and Password using WMI in C#

The below C# code sample uses the WMI class Win32_Service to update windows service user name and password. To use WMI service, we need to add the reference System.Management.

Note: Use the fully qualified user name (i.e. TestDomainMorgan) instead of simple user name (Morgan) if your remote computer is connected with Active Directory domain.

using System.Management;
//--------------------------
public static void ChangeServiceAccountInfobyWMI(string serviceName, string username,
          string password)
{
    string mgmntPath = string.Format("Win32_Service.Name='{0}'", serviceName);
    using (ManagementObject service = new ManagementObject(new ManagementPath(mgmntPath)))
    {
        object[] accountParams = new object[11];
        accountParams[6] = username;
        accountParams[7] = password;
        uint returnCode = (uint)service.InvokeMethod("Change", accountParams);
        if (returnCode == 0)
        {
             Console.WriteLine("Service account information changed successfully");
        }
        else
        {
             Console.WriteLine("Failed to change Service account information");
             Console.WriteLine("Error code: " + returnCode);
             // Support link to check the message for corresponding Return code:
             // https://msdn.microsoft.com/en-us/library/aa393660(v=vs.85).aspx
        }
    }
}

Update Service Account Username and Password in Remote Server

Use the below C# code sample to update windows service user name and password in remote machine using the WMI class Win32_Service. To use WMI service, we need to add the reference System.Management and use admin credentials if required to update service information in remote computer.

Note: Use the fully qualified user name (i.e. TestDomainMorgan) instead of simple user name (Morgan) if your remote computer is connected with Active Directory domain.

If you are receiving error code, get the error message for corresponding return code from this Microsoft support link: https://msdn.microsoft.com/en-us/library/aa393660(v=vs.85).aspx

using System.Management;
//--------------------------
static void ChangeRemoteServiceAccountInfo(string remoteComputer, string serviceName, 
            string username, string password)
{
    try
    {
        ConnectionOptions connectionOptions = new ConnectionOptions();
        // Use credentials if needed
        //connectionOptions.Username = "Administrator";
        //connectionOptions.Password = "AdminPassword";
        //connectionOptions.Impersonation = ImpersonationLevel.Impersonate;
        ManagementScope scope = new ManagementScope("\" + remoteComputer + 
                                             "rootCIMV2", connectionOptions);
        scope.Connect();
        string mgmntPath = string.Format("Win32_Service.Name='{0}'", serviceName);
        using (ManagementObject service = new ManagementObject(scope,
                                 new ManagementPath(mgmntPath),new ObjectGetOptions()))
        {
            object[] accountParams = new object[11];
            accountParams[6] = username;
            accountParams[7] = password;
            uint returnCode = (uint)service.InvokeMethod("Change", accountParams);
            if (returnCode == 0)
            {
                Console.WriteLine("Service account information changed successfully");
            }
            else
            {
                Console.WriteLine("Failed to change Service account information");
                Console.WriteLine("Error code: " + returnCode);
                // Support link to check the message for corresponding Return code:
                // https://msdn.microsoft.com/en-us/library/aa393660(v=vs.85).aspx
            }
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.ToString());
    }
}