I am trying to create a server for small business.But I could not chose OS for thıs .Am I use Linux or Windows 7 is enough and stable for home-build server?I will use Xampp.And I have a little experiment on Linux.But if it will be more stable then I can start to learn it .
If you use XAMPP I would say, that is doesn't matter which OS you take as XAMPP does everything out of the box.
I am also more a Windows user but I have two real web servers I administer and learning some bacis Linux commands is not that hard. The advantages using linux is that you already have some libraries installed that are not standard on Windows machines, such as Python, SVN, SSH and others. Also installing them is most of the time very easy using something like apt-get (Ubuntu) or zypper (openSuse).
You may find interesting the following articles:
Basic Advantages Of Linux Server Hosting And Windows Server Hosting - ezinearticles
Why do hosts prefer Linux to Windows Server? - serverfault
What are the advantages of the Linux server over the Windows server? - serverfault
Why would I use Windows Server over Linux? - serverfault