[c#] How do I get the currently-logged username from a Windows service in .NET?

I have a Windows service which need the currently logged username. I tried System.Environment.UserName, Windows identity and Windows form authentication, but all are returning "System" as the user as my service is running in system privileged. Is there a way to get the currently logged in username without changing my service account type?

Modified code of Tapas's answer:

Dim searcher As New ManagementObjectSearcher("SELECT UserName FROM Win32_ComputerSystem")
Dim collection As ManagementObjectCollection = searcher.[Get]()
Dim username As String
For Each oReturn As ManagementObject In collection
    username = oReturn("UserName")
Next

This is a WMI query to get the user name:

ManagementObjectSearcher searcher = new ManagementObjectSearcher("SELECT UserName FROM Win32_ComputerSystem");
ManagementObjectCollection collection = searcher.Get();
string username = (string)collection.Cast<ManagementBaseObject>().First()["UserName"];

You will need to add System.Management under References manually.

Try WindowsIdentity.GetCurrent(). You need to add reference to System.Security.Principal

If you are in a network of users, then the username will be different:

Environment.UserName

Will Display format : 'Username', rather than

System.Security.Principal.WindowsIdentity.GetCurrent().Name

Will Display format : 'NetworkName\Username'

Choose the format you want.

Just in case someone is looking for user Display Name as opposed to User Name, like me.

Here's the treat :

System.DirectoryServices.AccountManagement.UserPrincipal.Current.DisplayName.

Add Reference to System.DirectoryServices.AccountManagement in your project.

ManagementObjectSearcher("SELECT UserName FROM Win32_ComputerSystem") solution worked fine for me. BUT it does not work if the service is started over a Remote Desktop Connection. To work around this, we can ask for the username of the owner of an interactive process that always is running on a PC: explorer.exe. This way, we always get the currently Windows logged-in username from our Windows service:

foreach (System.Management.ManagementObject Process in Processes.Get())
{
    if (Process["ExecutablePath"] != null && 
        System.IO.Path.GetFileName(Process["ExecutablePath"].ToString()).ToLower() == "explorer.exe" )
    {
        string[] OwnerInfo = new string[2];
        Process.InvokeMethod("GetOwner", (object[])OwnerInfo);

        Console.WriteLine(string.Format("Windows Logged-in Interactive UserName={0}", OwnerInfo[0]));

        break;
    }
}

Completing the answer from @xanblax

private static string getUserName()
    {
        SelectQuery query = new SelectQuery(@"Select * from Win32_Process");
        using (ManagementObjectSearcher searcher = new ManagementObjectSearcher(query))
        {
            foreach (System.Management.ManagementObject Process in searcher.Get())
            {
                if (Process["ExecutablePath"] != null &&
                    string.Equals(Path.GetFileName(Process["ExecutablePath"].ToString()), "explorer.exe", StringComparison.OrdinalIgnoreCase))
                {
                    string[] OwnerInfo = new string[2];
                    Process.InvokeMethod("GetOwner", (object[])OwnerInfo);

                    return OwnerInfo[0];
                }
            }
        }
        return "";
    }

You can also try

System.Environment.GetEnvironmentVariable("UserName");