Programmatically instantiate the password login dialog

hmCoreDll = (HMODULE) LoadLibrary(_T("coredll.dll"));
gpfnShowStartupWindow = (PFN_ShowStartupWindow) GetProcAddress(hmCoreDll, _T("ShowStartupWindow"));

#include <windows.h>

// We need to declare these functions here because they are defined
// in pwinbase.h (contrary to what MSDN help for "SetPassword" tells
// us!) and pwinbase.h is not included as an SDK header file.
// Therefore to use these functions without needing access to all
// Platform Builder include files, we have to define them ourselves.
extern "C"
{
    BOOL SetPassword (LPWSTR lpszOldpassword, LPWSTR lspzNewPassword);
    BOOL SetPasswordStatus(DWORD dwStatus, LPWSTR lpszPassword);
}

// Forward declarations
bool InitPassword(LPWSTR pszOldPassword, LPWSTR pszNewPassword);

// Defines
#define PASSWORD_STATUS_ACTIVE              1
#define PASSWORD_STATUS_SCREENSAVERPROTECT  2

// Typedef'ed functions
typedef BOOL (WINAPI *PFN_ShowStartupWindow)(void);

int _tmain(int argc, _TCHAR* argv[])
{
    BOOL bRet = false;
    HMODULE hCoreDll = NULL;
    PFN_ShowStartupWindow pfnShowStartupWindow = NULL;

    // Create and activate password
    // (you can supply the current ("old") password on the command line)
    LPWSTR pszOldPassword = (argc > 1) ? argv[1] : NULL;
    if (InitPassword(pszOldPassword, L"password"))
    {
        hCoreDll = (HMODULE) LoadLibrary(L"coredll.dll");
        if (hCoreDll)
        {
            pfnShowStartupWindow = (PFN_ShowStartupWindow)GetProcAddress(hCoreDll, L"ShowStartupWindow");
            if (pfnShowStartupWindow)
                bRet = pfnShowStartupWindow();
            else
                RETAILMSG(1, (L"Failed to get address of \"ShowStartupWindow\" in coredll.dll, error %d\r\n", GetLastError()));
            FreeLibrary(hCoreDll);
        }
        else
            RETAILMSG(1, (L"Failed to load coredll.dll, error %d\r\n", GetLastError()));
    }
    return (int)bRet;
}

bool InitPassword(LPWSTR pszOldPassword, LPWSTR pszNewPassword)
{
    bool bRet = false;
    // Please note that the password must be lower case when you set it!
    // The password dialog box (code in startui.cpp) always converts the
    // user entered password to lower case before the compare!
    if (!SetPassword(pszOldPassword, pszNewPassword))
        RETAILMSG(1, (L"Failed to set the password, error %d\r\n", GetLastError()));
    //Set the password status
    else if (!SetPasswordStatus(PASSWORD_STATUS_ACTIVE | PASSWORD_STATUS_SCREENSAVERPROTECT, pszNewPassword))
        RETAILMSG(1, (L"Failed to set the password status, error %d\r\n", GetLastError()));
    else
        bRet = true;
    return bRet;
}

//      Get text from password window.
SendMessage(hwndPass, WM_GETTEXT, PASSWORD_LENGTH + 1, (LPARAM)szText);
_wcslwr(szText);
isAuthValid = (CheckPassword(szText) != FALSE);