Thank to ottoramsaig and Markoz but the problem persists. I tried to start the engines with and without battery, according to various published checklists, including the official manual, following several videos from youtube. It is useless. Sometimes it works and sometimes not. Sometimes I can start four engines, three, sometimes none. I'm desperate and disillusioned. Any suggestions on settings for win7, FSX or FSUIPC can solve the problem?.

Thank you very much everyone.