[muststopmyths]

I don't believe Windows CE had DirectX until later, so there probably wasn't any compatibility path.

Edit: apparently wrong again! not my day today.

[ThrowawayB7]

It's been a while but IIRC it was a cut down version of DirectX 5 ported from desktop Windows.

[dfox]

Windows CE as an OS has lot of peculiarities. For essentially single-tasking game console most of them are probably irrelevant, but on the other hand these peculiarities would probably make straight port of typical DirectX game from desktop windows an interesting endeavor.

[tasogare]

> The Sega Dreamcast is known for running an optimised version of Windows CE (with DirectX) as an operating system.

From the page linked.