text: i just downloaded messenger and now i cant sign in. why is this?   to be able to use the messenger,you have to disable your firewall.  for xp users,these are the steps that might help you.  to disable the windows xp firewall:     click [start] then click [control panel].    click [network and internet connections].   click [network connections].     select the step that is appropriate to your situation:     if you are using a dial-up connection, double-click [dial-up connection].     if you are using adsl or a cable modem, double-click [high speed or lan connection].     click the [general] tab in the connection status dialog box.    click the [properties] button.    click the [advanced] tab in the connection properties dialog.    clear the [internet connection firewall] check box.    click [ok].    hope it helps:-)