There are 2 types of operating system platforms which are used to host web site, namely: Windows and Unix. Each has its own features, advantages and disadvantages.
It is very difficult to say that there is always a better choice. The web language in which your website is programmed primarily dictates type of web hosting that you need.
Note: Operating system which is being uses on your personal computer has nothing to do with one which your webhost needs to serve your site. Most of the personal websites are developed with MS FrontPage and a Microsoft product , this can be hosted on a UNIX server with FrontPage Extensions which are installed.
Stability: UNIX systems are winners in this category. There are number of factors which are very useful : UNIX handles huge server loads as comparatively to Windows and UNIX machines seldom the required rebooting whereas Windows needs a constant rebooting. Web Servers run on UNIX and enjoy high availability, reliability and up-time.
Performance: There is a debate that which operating system’s performance is better, answer is that both perform comparably in a very low stress conditions whereas UNIX servers work under high loads which are superior to the Windows.
Scalability: Web sites change over the period of time. They all start small and grow as per requirement of a person or an organization. Both of these platforms can adapt to growing needs, Windows hosting is easily compatible as compared with a UNIX-based features like MySQL and PHP. UNIX software is not 100% compatible with technologies based on Microsoft like VB and .NET development. So if you want to use all these, you should select Windows hosting.
Compatibility: Web sites are being designed and programmed to serve under UNIX-based server this can be easily hosted on Windows web server, whereas reverse is not true. This helps to make programming for UNIX a better choice.
Price: Windows 2003 and web related applications like SQL Web Server, cost is a significant amount of price; on the other hand, Linux is a free OS which is used to download, operate and install. Windows hosting is a more expensive platform.