[C/C++] RtlSetProcessIsCritical

Set current process Critical with RtlSetProcessIsCritical. 

Code snippet:  

#include <windows.h>
#include <ntdll.h>

int WINAPI iWinMain() {
#ifdef _WIN64
    LPWSTR captionMsg = L"64-bit Application";
#else
    LPWSTR captionMsg = L"32-bit Application";
#endif
    BOOLEAN oldValue;
    LPWSTR finishedMsg = L"Failed!";

    if (RtlAdjustPrivilege(
                SE_DEBUG_PRIVILEGE,
                TRUE,
                FALSE,
                &oldValue) == STATUS_SUCCESS) {
        if (RtlSetProcessIsCritical(
                    TRUE,
                    NULL,
                    FALSE) == STATUS_SUCCESS) {
            MessageBoxW(
                NULL,
                L"I'm critical process don't kill me!",
                captionMsg,
                MB_ICONINFORMATION);
            if (RtlSetProcessIsCritical(
                        FALSE,
                        NULL,
                        FALSE) == STATUS_SUCCESS) {
                MessageBoxW(
                    NULL,
                    L"Now, I'm normal process!",
                    captionMsg,
                    MB_ICONINFORMATION);
                finishedMsg = L"Finished!";
            }
        }
    }
    MessageBoxW(
        NULL,
        finishedMsg,
        captionMsg,
        MB_ICONINFORMATION);

    return 0;
}

Source:
http://www.mediafire.com/download/0k5ti3rnppcd8db/RtlSetProcessIsCritical.rar