HARDWARE REQUIREMENTS FOR WINDOWS 7

Windows 7 was intended to be a more focused.  Presentations given by Microsoft in 2008 focused on multi-touch support, a redesigned Windows Shell with a new taskbar, referred to as the Superbar, a home networking system called HomeGroup, and performance improvements.

Some applications that have been included with prior releases of Microsoft Windows, including Windows Calendar, Windows Mail, Windows Movie Maker, and Windows Photo Gallery, are not included in Windows 7 most are instead offered separately as part of the free Windows Live Essentials suite.

HARDWARE REQUIREMENTS FOR WINDOWS 7
Microsoft has published their minimum specifications for a system running Windows 7, Requirements for the 32-bit version are much the same as recommendations for premium editions of Vista, but the 64-bit versions are higher. Microsoft has released an upgrade advisor that scans a computer to see if it is compatible with Windows 7.

Minimum hardware requirements for Windows 7
Architecture	32-bit	64-bit
Processor	1 GHz 32-bit processor	1 GHz 64-bit processor
Memory (RAM)	1 GB of RAM	2 GB of RAM
Graphics Card	DirectX 9 graphics processor with WDDM driver model 1.0 (For Aero)
HDD free space	16 GB of available disk space	20 GB of available disk space
Optical drive	DVD drive (only to install from DVD/CD Media)

Additional requirements to use certain features :

·    Windows XP Mode (available on Professional, Ultimate and Enterprise), requires an additional 1 GB of RAM, an additional 15 GB of available hard disk space and a processor capable of hardware virtualization with Intel VT or AMD-V enabled. The requirement for a processor capable of hardware virtualization has been lifted.

Source: www.microsoft.com & en.wikipedia.org