Make Windows 7 Look Like Mac OS X : Snow Transformation Pack

Snow Transformation Pack (Link) Make Windows 7Look Like Mac OS X

The Snow Transformation Pack works with Windows 7 both (32 and 64 bit) and Windows Vista, and as you can see from the screenshot below, it give your Windows PC a Mac OS X style desktop.

 

There are a few manual tweaks you can make to make even look more Mac-like (such right clicking on the Taskbar, hitting Properties, and checking "Use Small Icons" in the Taskbar tab), but overall it looks pretty good.

Also See : Change Windows 7 Logon, Welcome Screen Background