Does New Architecture Limit Backwards Compatibility?
Previously, Windows hasn’t been available for any device running non-Intel or non-AMD architecture, so offering support for ARM devices is quite a diversion for Microsoft.
However, while the basics of the operating system and user interface are expected to remain the same from device to device, it won’t be possible to run the same software on a medium spec laptop and on a tablet.
For instance, many games and applications depend on the presence of a particular specification of CPU, RAM and hard disk space – not to mention graphics memory – in order to run. Without these present, backwards compatibility for such software will not be possible if you attempt to install on a tablet or low spec notebook or netbook.
The minimum spec for the developer preview of Windows 8 - a release for developers to tune their existing applications and develop new ones for the new OS - is a 1 GHz x86 or x86-64 processor, 1 GB of RAM for 32-bit systems or 2 GB for 64-bit architecture, DirectX 9 capable graphics, 16 GB of HDD for the 32-bit version, 20 GB of HDD for the 64-bit release and a screen resolution of 1024x768 to use Metro.
Devices with a touch screen interface will also benefit, although this isn't necessary.
Going forward, the system requirements for the various types of supported device will be very different.