How can you be sure? Even I tried alky for few days but all was in vain.
Is it DXDiag tool which shows directX version as 10 ?
Is it some in-game settings which clearly shows that a DX10 feature is enabled in XP (like, in Bioshock
DX10 Lighting is enabled in Vista but not in XP)
In my trial of Alky under XP-Sp2, Bioshock didn't enable that settings but in vista (without alky of course) it is enabled and by default on.
Simply putting those dll files doesn't mean it's working. Because when I tried, all the games ran smoothly but neither DXDiag nor Bioshock could prove that DX10 is enabled under XP.
Waiting for some screens?