Urgent: funciton mail()!!!!!!

Hi webmaster, I have php in my Windows 2000 server. But when I try to send a form to a mail it doesn't work. There is something weir, because I don't receive the mail, and I don't receive any error from php. Actually the result of the line mail("wendyangulo@hotmail.com","Form","Sent") is 1. I read in a forum, that I have to uncomment the line from php.ini extension=php_nsmail.dll But it doesn't appear, can I put in the file and it will work?????? Do I have to restart something to get some effects? Do I missing some configuration in the server? Thanks Wendy Angulo