Create a process in Windows.

win.c

#include <windows.h>

int main(void) {
  // `STARTUPINFO` structure specifies the main window properties of a new
  // process, if one is created. I guess the name "Windows" is not for nothing,
  // GUIs are very important for it.
  STARTUPINFO si;
  // `PROCESS_INFORMATION` structure specifies information about a new process
  // and its primary thread. More in line with what one would except from an OS
  // API.
  PROCESS_INFORMATION pi;

  ZeroMemory(&si, sizeof(si));
  ZeroMemory(&pi, sizeof(pi));

  // Specifies the size, in bytes, of the structure.
  si.cb = sizeof(si);

  // `CreateProcess` returns a boolean indicating success.
  if(CreateProcess(
        // Module to execute. Can be set to `NULL` in which case the system
        // will get the module from the second argument.
        NULL,
        // Command line to execute.
        "C:\\WINDOWS\\System32\\mspaint.exe",
        // Security attributes. `NULL` means that the process handle is not
        // inheritable by child processes.
        //
        // A handle, from what I understand, is similar to `pid_t` in the Unix
        // world and "not inheritable" means that other processes created from
        // this one will not be able to use the handle to this Microsoft Paint
        // process.
        NULL,
        // Thread attributes. Similar to security attributes: `NULL` means the
        // handle is not inheritable.
        NULL,
        // Inherit handles. Indicates whether the _new_ process, i.e.
        // Microsoft Paint, can inherit the handles from the parent.
        FALSE,
        // Creation flags.
        0,
        // Environment block. If `NULL` inherit from the parent.
        NULL,
        // Working directory. If `NULL` inherit from the parent.
        NULL,
        &si,
        &pi)) {
    WaitForSingleObject(pi.hProcess, INFINITE);
  }

  CloseHandle(pi.hProcess);
  CloseHandle(pi.hThread);

  return 0;
}