Schtasks does not provide full access to the program

Question

I wrote a small code in C, and want to try to run it through Schtasks. It started, but a winapi function, which requires administrator rights, did not work.

For cmd, I use this prompt (I launched it with administrator rights):

schtasks /create /ru SYSTEM /tn TestTask /tr "C:\Users\Koalko\Desktop\main.exe" /sc ONSTART

I also tried to add my profile to the Administrators group, but that didn't change anything:

net localgroup Administrators Koalko /add

My C code:

#include <stdio.h>
#include <Windows.h>

int main(int argc, char* argv[]) {
    for (int i = 0; i <= 5; i++) {
        printf("\rBLOCK INPUT AFTER %d SECONDS", 5-i);
        Sleep(1000);
    }
    printf("\nBLOCK INPUT ON 5 SECONDS!!!\n");
    BlockInput(TRUE);
    Sleep(5000);
    BlockInput(FALSE);
    printf("RELEASE INPUT\n");
    getchar();
    return 0;
}

I don't think there is a problem in the code.

Answer 1

Thank a lot to IInspectable and Remy Lebeau. The issue was that the program was running in a non-interactive session, therefore BlockInput could not be executed. After reviewing the schtasks documentation, I found the /IT attribute which allows tasks to run in an interactive session. It is important to note that this attribute does not work with the SYSTEM user and is not executed with /sc ONSTART.

schtasks /create /ru Koalko /tn TestTask /tr "C:\Users\Koalko\Desktop\main.exe" /sc ONLOGON /RL HIGHEST /IT /f