Microsoft Windows 7 Professional 64-bit 1-Pack for $124.99

Easier to use. Simplify your PC with new navigation features like Aero Shake, Jump Lists, and Snap. Customize Windows to look and feel the way you like by changing themes and taskbar programs. Easy to network (with or without a server). Back up your complete system over a network. Faster and more flexible. Designed to make your PC sleep and resume quicker.