Outlook Web Access “Page not found”

After migrating users from an 2000 server to 2003 running Sharepoint and IIS, Outlook web Access returns error “page not found”. We have tried the Microsoft fixes in the KB with no avail. Access from an explicit IP address or internal returns error. How do I find what default settings for “Default Web Site” permissions, direcory security, etc. Problem is, everything worked before migrating users, now nothing. Internal Sharepoint services even went away.

Thanks in advance.

kdg138