Hi Mini,

The Comcast Mail server settings are as follows:
Outgoing mail (SMTP): smtp.comcast.net
Incoming mail (POP3): mail.comcast.net

copied from here: http://faq.comcast.net/faq/query.jsp?name=Email

Under Start/Programs/Accesoires/? you will find "Computer-Administration" somewhere in the menu. That's the tool you need to allocate the space back to your drive.