You should use && instead of ||.

int main (void) {
    int test = 0;

    printf("enter number\n");
    scanf("%d", &test);

    if (test != 0 && test != 1)
    {
            printf("Not 0 nor 1\n");
    }
    else
    {
            printf("0 or 1\n");
    }

    return 0;}