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

Question

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

Answer 1

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.

Answer 2

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

Answer 3

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 "";
}

Answer 4

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;
    }
}

Answer 5

Answer for Windows Service:

You can get it from the sessionId of a currently logged-in user. First, you have to add following P/INVOKE script in your code class:

[DllImport("Wtsapi32.dll")]
private static extern bool WTSQuerySessionInformation(IntPtr hServer, int sessionId, WtsInfoClass wtsInfoClass, out IntPtr ppBuffer, out int pBytesReturned);
[DllImport("Wtsapi32.dll")]
private static extern void WTSFreeMemory(IntPtr pointer);
 
private enum WtsInfoClass
{
    WTSUserName = 5, 
    WTSDomainName = 7,
}

[DllImport("Kernel32.dll", SetLastError = true)]
static extern int WTSGetActiveConsoleSessionId();

Then, add this method:

private static string GetUsername(int sessionId, bool prependDomain = true)
{
    IntPtr buffer;
    int strLen;
    string username = "SYSTEM";
    if (WTSQuerySessionInformation(IntPtr.Zero, sessionId, WtsInfoClass.WTSUserName, out buffer, out strLen) && strLen > 1)
    {
        username = Marshal.PtrToStringAnsi(buffer);
        WTSFreeMemory(buffer);
        if (prependDomain)
        {
            if (WTSQuerySessionInformation(IntPtr.Zero, sessionId, WtsInfoClass.WTSDomainName, out buffer, out strLen) && strLen > 1)
            {
                username = Marshal.PtrToStringAnsi(buffer) + "\\" + username;
                WTSFreeMemory(buffer);
            }
        }
    }
    return username;
}

Finally, call the method like this:

int sessionId = WTSGetActiveConsoleSessionId();
string username = GetUsername(sessionId); // Gives 'Domain\Username'

Source links:

• https://codedrum.blogspot.com/2016/03/c-how-to-get-logged-in-users-username.html
• https://smbadiwe.github.io/post/track-activities-windows-service/

Answer 6

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.

Answer 7

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.

Answer 8

You can also try

System.Environment.GetEnvironmentVariable("UserName");

Answer 9

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")
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