Differences between WindowsXP and Windows7

WindowsXP: User profiles are stored in C:\Documents and Settings
Windows7: User profiles are stored in C:\Users


WindowsXP: All Users Profile is stored in C:\Documents and Settings\All Users location
Windows7: All Users profile is stored in C:\ProgramData location


WindowsXP: User Account Control is absent
Windows7: User Account Control is present to avoid unwanted changes to System locations


WindowsXP: No Session Zero isolation
Windows7: Session Zero isolation present. Please refer to following URL for more information on Session Zero isolation
http://windowsteamblog.com/windows/b/developers/archive/2009/10/01/session-0-isolation.aspx