Do you like new windows 8 style? if yes maybe you like to have it in win7 too! so our friends mare-m ported windows 8/8.1 visual style for windows 7.
This is a really nice and same as the real win8 theme, also its have win8 boot screen and logon screen for win7.
You need to copy theme in C:\Windows\Resources\Themes
For using this theme first you need to Patch Uxtheme.