@Ruudboek: you were not quite correct in your analysis: You quoted %ATI%=ATI_HDC,NTx86.5.1, as if it were the line that identifies the installation section for the Windows 2000 driver installation. That is not correct, this is the section that calls the Windows 2000 driver installation: [ATI_HDC] %PCI\VEN_1002&DEV_4349.DeviceDesc% = atiide_Inst2k, PCI\VEN_1002&DEV_4349 Note the '[ATI_HDC]'. This is the one that calls the Windows XP driver installation: [ATI_HDC.NTx86.5.1] %PCI\VEN_1002&DEV_4349.DeviceDesc% = atiide_Instxp, PCI\VEN_1002&DEV_4349 Note the '[ATI_HDC.NTx86.5.1]'. I think you understand the difference now. No, the thing that matters is this: LoadOrderGroup = System Bus Extender, which can be found in both atiide.inf and Atihdc.inf. I did not notice this when I added these drivers the first time. I should have. This means I'll have to integrate these drivers as if they were equal to pciide.sys/aliide.sys, etc. A fix is being constructed...