Windows 7 RC is finally available for download from official Microsoft website for free. Though you can freely use Windows 7 RC (Release candidate) till March 1 2010. This gives users enough time to test drive Windows 7, which is surely looked forward to as a good Vista Replacement.
Minimum system requirements
1GHz 32-bit or 64-bit processor
1GB of RAM
16GB of disk space (or 20GB for 64-bit users)
DirectX 9 graphics device with WDDM 1.0 or higher driver
If you want to run the Window XP mode in Windows 7, Microsoft recommends a PC with a minimum of 2GB of memory and 15 GB of additional disk space.