Windows 7 is no doubt better than its earlier previous versions of the OS with the improved features of the GUI but there are people who like Windows XP so much that they do not wish to upgrade to the Win 7 OS only because of this.
If you also like the XP more than Windows 7 but also wanted to try and test the features of the Win 7 then you can install the Windows XP theme on the Windows 7. You might already know that the default theme of Windows XP is called as Luna.
The theme would transform your Windows 7 system into Windows XP as if you are using it. Windows XP theme for Windows 7 can be downloaded from the link below and if you face problems in installing the theme then this post should help you out.