GHz? Technically, you need at least the following to run Home Premium:
1 GHz 32-bit (x86) or 64-bit (x64) processor).
1 GB of system memory.
Support for DirectX 9 graphics with a WDDM driver, 128 MB of graphics memory (minimum), Pixel Shader 2.0 and 32 bits per pixel.
40 GB of hard drive capacity with 15 GB free space.