An Idea about the version of .Net Framework comes default in which Operating System

1. Windows XP and before don’t come with any version of .Net
2. Windows Server 2003 comes with .Net 1.1
3. Windows Vista comes with .Net 3.0
4. Windows 2008 comes with .Net 3.0
5.  Windows 2008 R2 comes with .Net 3.5
6. Windows 7 comes with .Net 3.5

Check one image showing the .Net Framework version comes default in OS