Microsoft is now taking pre-orders for Windows 8.1 from its Microsoftstore.com. Windows 8.1 costs $119.99 for a full version, which means you need not have a previous versions of Windows to install this OS. If you’re running Windows 8, visit the Windows Store for a free update to Windows 8.1 starting on October 17. If you’re running Windows 7, your files will easily transfer. If you’re running Windows Vista or earlier, qualify for the free upgrade to Windows 8.1 by purchasing Windows 8 now.