Ajith,
You can also put on you page:
<%@ Page Language="
VB" debug="true"%>
Not that at times the messages make any sense but it you have made a error it all becomes too apparent.
Microsoft Visual Web Developer 2008 is free to download and there is definitely error correction embedded. If you are running IIS 5 it is unlikely to be Vista, IIS6 is a definite improvement as you can set-up multiple instances of web sites.
Simon