Taken from PCWorld Magazine, February 2013

Classic Shell may be the ultimate free tool for bypassing Windows 8’s controversial tile-based interface.  Once installed, you will see a new icon in the lower-left corner of Desktop Mode’s taskbar.  Click it, and a Windows Start menu very like the one in Windows Vista or Windows 7 will appear.  In the Settings window, toward the bottom of the Basic Settings tab, is an option for “Skip Metro Screen”. Uncheck this entry if you ever want to abandon Classic Shell and restorer the normal Windows 8 desktop.  Click the “All Settings” button and you will get 13 tabs for further customizing your Start menu.

So, if you are stuck with buying a system with Windows 8 installed, but want the look and feel of Windows 7, then Classic Shell is perfect for you!