Hi srinu1253
If you can see the portal through dispatcher so obviously your Cognos is ok, your setup of the IIS however is not. You mentioned a Windows XP OS, is this the 64 bit version by any chance? Also, try to create a second virtual directory pointing to the same webcontent folder, with read and read/execute for cgi-bin. One more thing, not too sure about IIS5.1, forgot, but IIS6 has this "enable All unknown CGI extension", can you check that as well?
Regards,
Z