Is there any way to run this faster?

Please help me to get this faster because right now it makes a decent CPU usage.

bool CMemory::IsProcessRunning(DWORD dwPID, char* szProcessName = NULL)
{
    HANDLE hPID = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);
    PROCESSENTRY32 pEntry;
    pEntry.dwSize = sizeof(pEntry);

    if (Process32First(hPID, &pEntry))
    {
        do
        {
            if (pEntry.th32ProcessID == dwPID && (!strcmp(pEntry.szExeFile, szProcessName) || szProcessName == NULL))
            {
                CloseHandle(hPID);
                return TRUE;
            }
        } while (Process32Next(hPID, &pEntry));
    }

    CloseHandle(hPID);
    return FALSE;
}

Any answer will be appreciated. Thanks.

By the way, I really like to use built-in WinAPI. Don't suggest any libraries please.