This is concerning Windows XP processes.
I have a process running, let\'s call it Process1. Process1 creates a new process, Process2, and saves its id.
Now,
You may find if a process (given its name or PID) is running or not by iterating over the running processes simply by taking a snapshot of running processes via CreateToolhelp32Snapshot, and by using Process32First and Process32Next calls on that snapshot.
Then you may use th32ProcessID field or szExeFile field of the resulting PROCESSENTRY32 struct depending on whether you want to search by PID or executable name. A simple implementation can be found here.