Unless you need Windows for something specific, it usually isn’t ideal.
The vast majority of websites and web applications on the internet today run on one or more Open Source technologies — languages like PHP or Ruby, apps like WordPress and Drupal, frameworks like Rails or Django.
It is possible to run any of these on a Windows machine. However — installation, package management, and administration are all going to be easier on Linux. The technologies are usually built and tested on Linux (or Mac, which is similar), there are more tools and utilities for Linux, tutorials and support documents tend to assume a Linux environment.
So — unless you need something specific, such as .NET — Windows does not tend to be a good choice for hosting most websites.
