Run process as administrator from a non-admin application

Question

From an application that is not being run as administrator, I have the following code:

ProcessStartInfo proc = new ProcessStartInfo(); proc.WindowStyle = ProcessWindowStyle.Normal; proc.FileName = myExePath; proc.CreateNoWindow = false; proc.UseShellExecute = false; proc.Verb = "runas"; 

When I call Process.Start(proc), I do not get a pop up asking for permission to run as administrator, and the exe is not run as administrator.

I tried adding an app.manifest to the executable found at myExePath, and updated the requestedExecutionLevel to

<requestedExecutionLevel level="requireAdministrator" uiAccess="false" /> 

With the updated app.manifest, on the Process.Start(proc) call, I get an exception, "The requested operation requires elevation."

Why isn't the .Verb action not setting administrator privileges?

I am testing on Windows Server 2008 R2 Standard.

Answer 1

You must use ShellExecute. ShellExecute is the only API that knows how to launch Consent.exe in order to elevate.

Sample (.NET) Source Code

In C#, the way you call ShellExecute is to use Process.Start along with UseShellExecute = true:

private void button1_Click(object sender, EventArgs e) {    //Public domain; no attribution required.    ProcessStartInfo info = new ProcessStartInfo(@"C:\Windows\Notepad.exe");    info.UseShellExecute = true;    info.Verb = "runas";    Process.Start(info); } 

If you want to be a good developer, you can catch when the user clicked No:

private void button1_Click(object sender, EventArgs e) {    //Public domain; no attribution required.    const int ERROR_CANCELLED = 1223; //The operation was canceled by the user.     ProcessStartInfo info = new ProcessStartInfo(@"C:\Windows\Notepad.exe");    info.UseShellExecute = true;    info.Verb = "runas";    try    {       Process.Start(info);    }    catch (Win32Exception ex)    {       if (ex.NativeErrorCode == ERROR_CANCELLED)          MessageBox.Show("Why you no select Yes?");       else          throw;    } } 

Bonus Watching

• UAC - What. How. Why.. The architecture of UAC, explaining that CreateProcess cannot do elevation, only create a process. ShellExecute is the one who knows how to launch Consent.exe, and Consent.exe is the one who checks group policy options.