Windows CE supports several processors. You will need to select a processor for your device from this list.
There are some additional initial requirements that are important to bear in mind when starting a project:
Windows CE RAM is restricted to 1GB, but in reality CE has been tested with devices only up to 32MB of RAM. You might end up using much less RAM on your target platform. But for a debug version of the platform, you should plan on adding much more RAM. You will also need to plan for either ROM or Flash memory for non-volatile storage. Windows CE 2.11 can use from 350KB of ROM for a minimal configuration to 5MB for a configuration packed with goodies.
CE debugging takes place by downloading an image to the target platform and collecting debug information over another channel or transport. Downloads in early versions of CE took place over a bidirectional parallel port. In version 2.10 and later, Ethernet support was added. This sped up the downloading process considerably. However, if your device uses Ethernet for networking, this transport will not be available for debugging. You will need to consider building a special development version of your platform that has two Ethernet interfaces on it, one of which is then reserved for debugging. A serial port is used by the CE kernel to communicate debugging information to the kernel debugger running on a workstation. This should be a design priority to facilitate debugging. You should make sure at an early stage that the hardware design will accommodate at least a parallel and serial port on the development platform, and preferably an Ethernet port.