As another point, Windows is MUCH more susceptible to virus infections, especially of the web page infection variety. Linux is much more secure in that regard because of how it deals with file system permissions and such, which is why most serious web sites use Linux (usually some variety of Red Hat Enterprise Linux such as RHEL, CentOS, etc) for their web hosting. We used CentOS exclusively at Nokia Mobile Phones (before being taken over by Microsoft) and we NEVER had a problem of that sort, and we were dealing with over 100 million users and billions of connections / pages served each day.
The highest difference among Windows hosting and Linux hosting are the technologies used by for environments:
If you take developed your website by PHP and MySQL and you are not by any Microsoft technologies i.e. ASP.Net, Microsoft SQL server etc. You can think through by Linux hosting
If you are by Microsoft technologies i.e. ASP.Net, Microsoft SQL server etc. to develop your website, you take to use Windows hosting platform to meet your essential. In Windows hosting, you can still use PHP and MySQL besides together are platform independent software. But best users choose to go for Linux hosting if they are only by PHP ad MySQL for their websites.
Now you can run SQL Server and .NET on Linux, the remaining differences are user familiarity and price. Linux is free but if you already use and know Windows, Linux might seem complicated. Also, Windows isn't as easy to administrate remotely and trickier to secure.