You can now try Windows 2008 server for 60 days free.
Click on the link and download the ISO image. You can burn the ISO image on a dvd with for example the program DeepBurner(www.deepburner.com) and after that boot from the dvd qnd install Windows 2008 server.
http://www.microsoft.com/windowsserver2008/en/us/default.aspx
