Hello,
You may create a bat file, below is the example, kindly change your variable in the bold text.
Function of the script is to start second.exe until your first.exe is running.
@echo off
:CheckFirstRunning
tasklist /FI "IMAGENAME eq first.exe" 2>NUL | find /I /N "first.exe">NUL
if "%ERRORLEVEL%"=="0" (
echo first.exe is running.
start "" second.exe
) else (
echo first.exe is not running. Waiting for it to start...
timeout /t 5 /nobreak >nul
goto CheckFirstRunning
)