Execute Processes from your application on Vista

When developing applications for Windows Vista, one of the problems that often arises is how to programmatically control the execution level of a process. When the user starts an application, its elevation level is determined by the value of the requestedExecutionLevel attribute in its manifest, and Vista’s User Account Control (UAC) takes appropriate actions depending on it (such as displaying the elevation prompt when needed, etc.) However, what if the application needs to start a new process with a different execution level than that of the application itself? For example:

• An application that runs at the standard level determines that an updated version of it is available for download. To be able to update itself, it needs to start a separate process that needs to be elevated in order to perform the upgrade properly. In this case a non-elevated process needs to start a new, elevated process.

If this is your case, then I have the answer for you.

By specifying the "runas" verb when calling the ShellExecuteEx API you can “tell” UAC that open this application and not just to blockit.

The code is fairly simple, i am using C++ here,

#include <windows.h>
ShellExecute(NULL,(LPCSTR)"runas",(LPCSTR)"yourprocess.exe",NULL,NULL,SW_SHOWNORMAL);

This is the ShellExecute API


HINSTANCE ShellExecute(
    HWND hwnd,
    LPCTSTR lpOperation,
    LPCTSTR lpFile,
    LPCTSTR lpParameters,
    LPCTSTR lpDirectory,
    INT nShowCmd
);

Parameter     Description
----------------------------------------------------------------------------
hwnd          Identifies the parent window. This window receives any
              message boxes an application produces (for example, for error
              reporting).

lpszOp        Points to a null-terminated string specifying the operation
              to perform. This string can be "open" or "print." If this
              parameter is NULL, "open" is the default value.

lpszFile      Points to a null-terminated string specifying the file
              to open.

lpszParams    Points to a null-terminated string specifying parameters
              passed to the application when the lpszFile parameter
              specifies an executable file. If lpszFile points to a string
              specifying a document file, this parameter is NULL.

LpszDir       Points to a null-terminated string specifying the default
              directory.

FsShowCmd     Specifies whether the application window is to be shown when
              the application is opened.