I use a Windows Server set up hosted on UpCloud. It's a Virtual Private Server, or VPS, which I control and maintain.
My server runs other server technologies, but the main one for me is the web server - Internet Information Services, or IIS.
This web server is one of the fastest and robust web servers on the market today.
As it is a VPS resources are drawn as needed from physical servers dotted around the world. Also, because of the nature of the cloud, the server is better protected from outages.
There is a lot of information about Windows Server on the internet, but the wiki entry is a good starting point.
Windows Server at Wikipedia: Windows Server
I offer hosting on my Windows Server starting at 20€ per month, which gives you approximately 50 gigs of storage, 2 gigs of RAM and more
bandwidth than you will be able to use. I can increase resources whenever they are needed ensuring that your website meets demand without
experiencing any downtime.
Note, if your website requires more resources this will incur additional hosting costs from 10€ per month.