VPS noob questions, please shine some light on me

Hello everyone,

I am going to buy my first VPS, and I know nothing about the VPS, hope that someone can explain these questions to me:

What is the difference between Linux and Windows?

And should I choose windows 2003 or 2008?

I need this vps to run some software that need .net 2.0

Hope that someone can help me

Linux and windows are operating systems and you say that you need a vps to run sofware so it is better to choose windows 2008