Why those two different behaviors with WaitForSingleObject function in CPP

Question

I have the following code sample:

#include 
#include 
#include 

using namespace std;

void main()
{
    SHELLEXEC         


        

Answer 1

I tried your code on Windows 10, and SysInternals Process Monitor shows the following:

As you can see, calc.exe spawns a new process and then ends, thus satisfying the wait. That is why you see your output immediately. This second process is the actual calculator process. In my case, it is located at this path:

C:\Program Files\WindowsApps\Microsoft.WindowsCalculator_10.1612.3341.0_x64__8wekyb3d8bbwe\Calculator.exe