DX10 - why not on XP?

[shaffaaf27]

Why couldn't DX10 be inplemented on XP. was it just to drive the sales of Vista, or could DX10 only use hardware and sytem coding from vista?

if it was down to the coding, couldn't a patch for XP be made?

 

[shaffaaf27]

but im sure if MS wrote it for vista, someone (inc MS) could write it for XP. if im correct DX10 is an API (like OpenGL), so why couldnt it be done?