Windows 7: Downgrade windows 7 homepremium 64 from DX11 to DX10 for compability?

Hi Experts,

I want to use Dungeon&Dragons online in 3-Dimensional setup with IT3Z drivers on ATI RAdeon HD5870 graphic card.

IT3Z gives a compatibel 3-D output for DX9 and beta DX10. First I got only error messages, but then installed DX9 in addition to DX11.
And know I can use the DX9 ITZ§ version with windows 7.



But I want to use the DX10 beta version, too. But I cant find a DX10 for windows7 ?
Can you help me what to do?

Best regards
Micael

Windows 7 already include DX9-11, you can't downgrade DX11 to 10

Use Vista SP2 compatibility mode for this game: Compatibility Mode

Is there any certain reason you want to use the DX10 beta over the final release?

-- Or is DnD doing a dx10 beta version of the game?

So why installing DX9 made a difference then in starting DDO togehter with IZ3D in DX9 if DX9-11 is included?

I think IZ3D search after special d3dx10_42.dII and d3dx9_42.dII and then starts DDO with 3- Dimensional input.
Otherwise I cant understand why an error message came up, that the mentioned dll are missing.

After installing DX9 and downloading both dii to the system32 directory the DX9 verson worked.

Best regards
Micael

The final release of IZ3D is only DX9 able- the beta uses DX10 but is a bit unstable.
DDO (dungeon&Dragons online) has both DX9+10 since a longer time and will upgrade to DX11 on 20.November 2010.
But since I want to play in 3-Dimensions I cant use the DX11 option from DDO till IZ3D also provide 3 dimensional output for DX11.

Best regards
Micael

compabillity mode is not helpfull- DDO still crashes if used in DX10 mode together with IZ3D- any more suggestions?

Best regards
Micael