WordPress is a breeze to install if you have PHP any MySQL in place. On Windows/IIS there are two dark holes, though.
One is URL rewriting and the other is sending email about comments, forgotten passwords etc. Let’s talk about the second one today.
If you enable SMTP email sending in php.ini you are halfway there. But there is a good chance SMTP server will not accept your email if the mailbox is not local, since WordPress sends email from hardcoded address wordpress@<your-domain>. Also, this will not work if your SMTP server requires authentication.
All this can be easily solved with Configure SMTP WP plugin. This plugin lets you configure SMTP sending details and even lets you use Gmail servers for sending mails. As usual, installation is dead simple, after you do it you just configure SMTP server details and it just works.