Windows 7 All in One:
System Requirements:
Processor: 1 gigahertz (GHz) or faster
RAM: 1 (GB) (32-bit) or 1 GB (64-bit)
Hard disk space: 16 GB (32-bit) or 20 GB (64-bit)
Graphics card: Microsoft DirectX 9 graphics device.
Windows 7 Home Premium x86 English Download link
Windows 7 Home Premium x64 English Download link
Windows 7 Professional x86 English Download link
Windows 7 Ultimate x86 English Download link
All in one Download link