Windows 7  is the latest version of Microsoft Windows, a series of operating systems produced by Microsoft for use on personal computers, including home and business desktops, laptops, netbooks, tablet PCs and media center PCs. Windows 7 was released to manufacturing on July 22, 2009 with general retail availability set for October 22, 2009

If you’d like to use Windows 7, make sure your computer has at least the following system requirements:

1 GHz 32-bit processor

Memory 1 GB of RAM

Graphics card with DirectX 9 graphics processor with WDDM driver model 1.0(For Aero)

HDD free space 16 GB of available disk space

Optical DVD drive (only to install from DVD/CD Media)

If you’re considering whether to update Windows XP computer with Windows 7, take a look at this article [igadgetlife.com]

it compares xp to vista performance on a lower end machines.