OpenProcess
GetModuleFileNameEx lub GetProcessImageFileName lub QueryFullProcessImageName
CloseHandle
EDIT
Nudzi mi się:
#include "stdafx.h"
#include <iostream>
#include "Windows.h"
#include "Psapi.h"
using namespace std;
int main(void) {
Sleep(3000);
HWND hOkno = GetForegroundWindow();
DWORD proccesID;
GetWindowThreadProcessId(hOkno, &proccesID);
wcout << "PID: " << proccesID << "\n\n";
HANDLE hProc = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, proccesID);
wchar_t processName[MAX_PATH];
wcout << "GetModuleFileNameEx:\n";
ZeroMemory(processName, MAX_PATH);
GetModuleFileNameEx(hProc, NULL, processName, MAX_PATH);
wcout << processName << "\n\n";
wcout << "GetProcessImageFileName:\n";
ZeroMemory(processName, MAX_PATH);
GetProcessImageFileName(hProc, processName, MAX_PATH);
wcout << processName << "\n\n";
wcout << "QueryFullProcessImageName:\n";
ZeroMemory(processName, MAX_PATH);
DWORD len = MAX_PATH;
QueryFullProcessImageName(hProc, 0, processName, &len);
wcout << processName;
CloseHandle(hProc);
wcin.get();
return 0;
}