从C＃以管理员身份运行shell命令（manage-bde）

Question

I need to run "manage-bde" shell command from C# code.

The main application process is already running as administrator and is Elevated.

I used code from : UAC self-elevation example on MS website for confirming the app process is elevated. ( http://code.msdn.microsoft.com/windowsdesktop/CSUACSelfElevation-644673d3 )

However, when I try to run manage-bde from the C# code, I get "System can't find file specified".

        Process p = new Process();
        p.StartInfo.FileName = "C:\\Windows\\System32\\manage-bde.exe";
        p.StartInfo.UseShellExecute = true;
        p.Start();

As a workaround, I tried to create a batch file that runs the command.

        string batchFileName = DateTime.Now.Ticks + ".bat";
        StreamWriter writer = new StreamWriter(batchFileName);
        writer.WriteLine("manage-bde");
        writer.Flush();
        writer.Close();               
        Process p = new Process();
        p.StartInfo.FileName = batchFileName;               
        p.StartInfo.UseShellExecute = true;                             
        p.Start();

The batch file is written , and executed successfully; However, the command "manage-bde" is not recognized.

I changed the code to use the verb "runas" and use admin password and that works, but I want the batch file to work without the need for providing the admin password. The current logged in user is already administrator on the computer but the batch file is not getting executed with the existing admin privileges . I need the batch file to execute and manage-bde to run successfully.

Your help or advice will be very highly appreciated :)

ps: some commands other than manage-bde work fine without need for admin runas.

Answer 1

The reason of the behavior I encountered was the Windows File System Redirector.

In most cases, whenever a 32-bit application attempts to access %windir%\\System32, the access is redirected to %windir%\\SysWOW64

https://msdn.microsoft.com/en-us/library/windows/desktop/aa384187%28v=vs.85%29.aspx

My application build was 32 bits. Whenever it tried to access System32 windows automatically redirected it to SysWow64 which does not contain "manage-bde.exe". I changed the build to 64 bits and then the application could access manage-bde.exe from System32

Answer 2

Even if you're running as the Administrator user, you're not fully elevated if UAC is running. Meaning that you'll have either the UAC prompt come up or you'll be prompted for a password.

The only real way you could get around that is to run your application elevated first, or to write a service that runs with elevated permissions to start your new process.

The alternative of course is to disable UAC, but that is undesirable in most situations.