well, it is not really transformation tough :). But using some software we can modify our windows to look like MAC. Some separated software exist and can be use, but there is complete package that you can use. This package will install new theme in our windows. So that in appearance setting we can choose MAC theme, which offers us MAC icon and appearance.

this is the example

To transform your windows into MAC you can download this package software called Lion Skin Pack. this software will help you to change all the windows icon into MAC icon once you install it. it will also set the sound into MAC sound, and set font environment into MAC font. Its nice, easy to install and easy to use.

Once you have installed this software, it will automatically activate its MAC Lion theme on your windows dekstop. But however you can choose which theme and you can modificate it. Just right click on your free space on desktop and choose personalisation and choose MAC. you can download Lion Skin Pack in link below :
here