WMI to reboot remote machine

Question

I found this code on an old thread to shutdown the local machine:

using System.Management;

void Shutdown()
{
    ManagementBaseObject mboShutdown = null;
    ManagementClass mcWin32 = new ManagementClass("Win32_OperatingSystem");
    mcWin32.Get();

    // You can't shutdown without security privileges
    mcWin32.Scope.Options.EnablePrivileges = true;
    ManagementBaseObject mboShutdownParams =
             mcWin32.GetMethodParameters("Win32Shutdown");

    // Flag 1 means we want to shut down the system. Use "2" to reboot.
    mboShutdownParams["Flags"] = "1";
    mboShutdownParams["Reserved"] = "0";
    foreach (ManagementObject manObj in mcWin32.GetInstances())
    {
        mboShutdown = manObj.InvokeMethod("Win32Shutdown", 
                                       mboShutdownParams, null);
    }
}

Is it possible to use a similar WMI method to reboot flag "2" a remote machine, for which i only have machine name, not IPaddress.

EDIT: I currently have:

SearchResultCollection allMachinesCollected = machineSearch.FindAll();
Methods myMethods = new Methods();
string pcName;
ArrayList allComputers = new ArrayList();
foreach (SearchResult oneMachine in allMachinesCollected)
{
    //pcName = oneMachine.Properties.PropertyNames.ToString();
    pcName = oneMachine.Properties["name"][0].ToString();
    allComputers.Add(pcName);
    MessageBox.Show(pcName + "has been sent the restart command.");
    Process.Start("shutdown.exe", "-r -f -t 0 -m \\" + pcName);
}

but this doesn't work, and I would prefer WMI going forward.

Answer 1

To address WMI queries to a remote computer, you simply specify that computer's name (or IP address) in the ManagementScope object.

I'm not well up in C#, but here's an example I came up with using MSDN and WMI Code Creator (which is, by the way, an excellent tool for generating WMI code, and supports C# among others). Hope this code will give you the idea.

(Disclaimer: This code is untested.)

using System;
using System.Management;
...

void Shutdown()
{
    try
    {
        const string computerName = "COMPUTER"; // computer name or IP address

        ConnectionOptions options = new ConnectionOptions();
        options.EnablePrivileges = true;
        // To connect to the remote computer using a different account, specify these values:
        // options.Username = "USERNAME";
        // options.Password = "PASSWORD";
        // options.Authority = "ntlmdomain:DOMAIN";

        ManagementScope scope = new ManagementScope(
          "\\\\" + computerName +  "\\root\\CIMV2", options);
        scope.Connect();

        SelectQuery query = new SelectQuery("Win32_OperatingSystem");
        ManagementObjectSearcher searcher = 
            new ManagementObjectSearcher(scope, query);

        foreach (ManagementObject os in searcher.Get())
        {
            // Obtain in-parameters for the method
            ManagementBaseObject inParams = 
                os.GetMethodParameters("Win32Shutdown");

            // Add the input parameters.
            inParams["Flags"] =  2;

            // Execute the method and obtain the return values.
            ManagementBaseObject outParams = 
                os.InvokeMethod("Win32Shutdown", inParams, null);
        }
    }
    catch(ManagementException err)
    {
        MessageBox.Show("An error occurred while trying to execute the WMI method: " + err.Message);
    }
    catch(System.UnauthorizedAccessException unauthorizedErr)
    {
        MessageBox.Show("Connection error (user name or password might be incorrect): " + unauthorizedErr.Message);
    }
}

Answer 2

I had trouble with this also. WMI can be misleading with methods for classes and object. My solution is for rebooting a host on the network with C# and WMI, but is easily simplified for local machine:

private void rebootHost(string hostName)
{
    string adsiPath = string.Format(@"\\{0}\root\cimv2", hostName);
    ManagementScope scope = new ManagementScope(adsiPath);
    // I've seen this, but I found not necessary:
    // scope.Options.EnablePrivileges = true;
    ManagementPath osPath = new ManagementPath("Win32_OperatingSystem");
    ManagementClass os = new ManagementClass(scope, osPath, null);

    ManagementObjectCollection instances;
    try
    {
        instances = os.GetInstances();
    }
    catch (UnauthorizedAccessException exception)
    {
        throw new MyException("Not permitted to reboot the host: " + hostName, exception);
    }
    catch (COMException exception)
    {
        if (exception.ErrorCode == -2147023174)
        {
            throw new MyException("Could not reach the target host: " + hostName, exception);
        }
        throw; // Unhandled
    }
    foreach (ManagementObject instance in instances)
    {
        object result = instance.InvokeMethod("Reboot", new object[] { });
        uint returnValue = (uint)result;

        if (returnValue != 0)
        {
            throw new MyException("Failed to reboot host: " + hostName);
        }
    }
}