ivanoe, I believe some of your facts are not correct. Window Live Mail (WLM), i.e. the free software that comes from Microsoft, is not part of a new Windows 7 installation. WLM must be downloaded and installed. You said you reinstalled windows 7. This means you would have to reinstall WLM since it's not integrated into Windows 7.
So, after you reinstalled Windows AND reinstalled WLM, you would have needed to create your email account in WLM. WLM makes creating new accounts easy. In most cases, you can simply enter your email address and email account password and then WLM will find the POP and SMTP coding, port #s for sending and receiving, etc. and automatically complete the account setup. The user can override this automatic method and manually setup up the account. Also, you could have exported your email account from WLM before you reinstalled Windows and then imported the email account after reinstalling Windows and WLM. So, exactly what have you done and how?