5. What is Marshalling not necessary?

Marshalling is the process of packaging and sending interface method parameters across thread, process or machine boundaries.

6. How to remotely administer MS IIS?

using these steps

1)IIS Manager

2) Terminal Services

3)Remote Administration (HTML) Tool

7. Explain Why do we use Option Explicit?

Option Explicit requires that all variable names be defined (with the Dim statement).

8. What is IUnknown and what are its three parts?

The COM interface class from which all other interface classes are derived. This interface allows all COM objects to manage their own lifetime, ie, to release themselves from memory when they are no longer connected to any clients.

IUnknown Interface is the Interface which every COM should have.
The Three parts are:
1. QueryInterface
2. Addref
3. release

9. Explain session variables?

Variabiles saved between the sessions (ASP, PHP etc.)
Can be stored in server side or client side (with cookies).