With the availability of the Release Candidate for Windows 7 operating system , Microsoft has also made public the system requirements for this windows 7 operating system. The good news for us? Users who have already moved to a Windows Vista operating system machine will not need to upgrade their hardware yet again just to accommodate Windows 7 operating system.
In fact, the system requirements for the Windows 7 operating system are roughly the same as for its precursor, with the Beta testers indicating that Windows 7 operating system outperforms Windows Vista on the same hardware. After testing using my current hardware, Windows 7 operating system is faster than Windows Vista operating system

System Requirements for Windows 7 are “1GHz or faster 32-bit (x86) or 64-bit (x64) processor; 1 GB of RAM (32-bit)/2 GB of RAM (64-bit); 16 GB of available disk space (32-bit)/20 GB (64-bit); DirectX 9 graphics device with Windows Display Driver Model 1.0 or higher driver,” according to Microsoft.

Windows 7 operating system  now available in :

Windows 7 Ultimate    
Windows 7 Enterprise
Windows 7 Professional
Windows 7 Home Premium    
Windows 7 Home Basic    
Windows 7 Starter