We are not going to get our hands on much anticipated Microsoft Windows 7 anytime soon, but we can enjoy the look and feel now on our Windows XP & Vista system's using the "Windows 7 Desktop Theme", Since not much details about the upcoming OS is available, the theme looks very similar to Windows Vista but provide some nice refreshing changes to the same old look.
1. Download Windows 7 Theme here >>
2. Install "UXTheme Multi-Patcher 6.0.exe" from "UX Theme Patcher" folder.
3. Double-click "Windows 7 M1 VS.msstyles" in "Theme\Windows 7 M1 VS" folder to install.
Source : http://www.megaleecher.net/Download_Windows_7_Theme