Users of VPS hosting have allocated resources just like Dedicated hosting users, however the amount of available resources on VPS servers may still not be what a website needs. For example, VPS servers often start at 2GB of RAM, whereas Dedicated servers often start with at least 4GB of RAM available. In short, Dedicated hosting allows for the same full customization and control of a VPS server, but with even more horsepower.
The answer to this question largely depends on two factors. Are you new to server technology and not very interested? In this case, Windows is the easiest option to get where you want to go. Do you already have experience with Linux or would you like to familiarize yourself with this operating system? If so, Linux gives you more freedoms to configure your server, and you will be using an operating system that is less vulnerable to attacks from the Internet. Linux is also open source and therefore free.