システム環境変数のPROCESSOR_ARCHITECTURE=AMD64を見てるのかな
一部のフォルダ、ファイル名に_amd64をくっ付けたらいけた

元々のフォルダ構成

C:.
│  Autorun.inf
│  ReleaseNotes.Htm
│  setup.exe
│  winsdk_dvdx86.msi
│
└─Setup
    │  SDKSetup.cab
    │  SDKSetup.exe
    │  custsat_amd64.dll
    │  custsat_ia64.dll
    │  custsat_x86.dll
    │
    ├─WinSDK
    │      WinSDK_x86.msi
    │      cab1.cab
    │
    ├─WinSDKApplicationVerifier
    │      ApplicationVerifier.x86.msi
    │
    ├─WinSDKApplicationVerifier_amd64
    │      ApplicationVerifier.amd64.msi
    │
    ├─WinSDKApplicationVerifier_ia64
    │      ApplicationVerifier.ia64.msi
    │
    ├─WinSDKBuild
    │      WinSDKBuild_x86.msi
    │      cab1.cab
    │      cab2.cab
    │      cab3.cab
    │      cab4.cab
    │
    ├─WinSDKDebuggingTools
    │      dbg_x86_6.11.1.404.msi
    │
    ├─WinSDKDebuggingTools_amd64
    │      dbg_amd64_6.11.1.404.msi
    │
    ├─WinSDKDebuggingTools_ia64
    │      dbg_ia64_6.11.1.404.msi
    │
    ├─WinSDKDocNetFx
    │      WinSDKDocNetFx_x86.msi
    │      cab1.cab
    │      cab10.cab
    │      cab11.cab
    │      cab12.cab
    │      cab13.cab
    │      cab14.cab
    │      cab15.cab
    │      cab16.cab
    │      cab2.cab
    │      cab3.cab
    │      cab4.cab
    │      cab5.cab
    │      cab6.cab
    │      cab7.cab
    │      cab8.cab
    │      cab9.cab
    │
    ├─WinSDKDocWin32
    │      WinSDKDocWin32_x86.msi
    │      cab1.cab
    │      cab2.cab
    │      cab3.cab
    │      cab4.cab
    │      cab5.cab
    │      cab6.cab
    │
    ├─WinSDKIntellisenseRefAssys
    │      WinSDKIntellisenseRefAssys_x86.msi
    │      cab1.cab
    │
    ├─WinSDKInterop
    │      WinSDKInterop_x86.msi
    │      cab1.cab
    │
    ├─WinSDKNetFxTools
    │      WinSDK_nfxtoolsm_x86.msi
    │      cab1.cab
    │
    ├─WinSDKRedist
    │      WinSDKRedist_x86.msi
    │      cab1.cab
    │      cab2.cab
    │      cab3.cab
    │
    ├─WinSDKSamples
    │      WinSDKSamples_x86.msi
    │      cab1.cab
    │      cab2.cab
    │      cab3.cab
    │      cab4.cab
    │      cab5.cab
    │
    ├─WinSDKTools
    │      WinSDKTools_x86.msi
    │      cab1.cab
    │      cab2.cab
    │
    ├─WinSDKWin32Tools
    │      WinSDKWin32Tools_x86.msi
    │      cab1.cab
    │
    ├─vc_stdamd64
    │      vc_stdamd64.cab
    │      vc_stdamd64.msi
    │
    ├─vc_stdia64
    │      vc_stdia64.cab
    │      vc_stdia64.msi
    │
    ├─vc_stdx86
    │      vc_stdx86.cab
    │      vc_stdx86.msi
    │
    └─winsdk_intellidocs
            winsdk_intellidocs.cab
            winsdk_intellidocs.msi

編集後のフォルダ構成

C:.
│  Autorun.inf
│  ReleaseNotes.Htm
│  setup.exe
│  winsdk_dvdx86.msi
│
└─Setup
    │  custsat_amd64.dll
    │  custsat_ia64.dll
    │  custsat_x86.dll
    │  SDKSetup.cab
    │  SDKSetup.exe
    │
    ├─vc_stdamd64
    │      vc_stdamd64.cab
    │      vc_stdamd64.msi
    │
    ├─vc_stdia64
    │      vc_stdia64.cab
    │      vc_stdia64.msi
    │
    ├─vc_stdx86
    │      vc_stdx86.cab
    │      vc_stdx86.msi
    │
    ├─WinSDKApplicationVerifier
    │      ApplicationVerifier.x86.msi
    │
    ├─WinSDKApplicationVerifier_amd64
    │      ApplicationVerifier.amd64.msi
    │
    ├─WinSDKApplicationVerifier_ia64
    │      ApplicationVerifier.ia64.msi
    │
    ├─WinSDKBuild_amd64
    │      cab1.cab
    │      cab2.cab
    │      cab3.cab
    │      cab4.cab
    │      WinSDKBuild_amd64.msi
    │
    ├─WinSDKDebuggingTools
    │      dbg_x86_6.11.1.404.msi
    │
    ├─WinSDKDebuggingTools_amd64
    │      dbg_amd64_6.11.1.404.msi
    │
    ├─WinSDKDebuggingTools_ia64
    │      dbg_ia64_6.11.1.404.msi
    │
    ├─WinSDKDocNetFx_amd64
    │      cab1.cab
    │      cab10.cab
    │      cab11.cab
    │      cab12.cab
    │      cab13.cab
    │      cab14.cab
    │      cab15.cab
    │      cab16.cab
    │      cab2.cab
    │      cab3.cab
    │      cab4.cab
    │      cab5.cab
    │      cab6.cab
    │      cab7.cab
    │      cab8.cab
    │      cab9.cab
    │      WinSDKDocNetFx_amd64.msi
    │
    ├─WinSDKDocWin32_amd64
    │      cab1.cab
    │      cab2.cab
    │      cab3.cab
    │      cab4.cab
    │      cab5.cab
    │      cab6.cab
    │      WinSDKDocWin32_amd64.msi
    │
    ├─WinSDKIntellisenseRefAssys_amd64
    │      cab1.cab
    │      WinSDKIntellisenseRefAssys_amd64.msi
    │
    ├─WinSDKInterop_amd64
    │      cab1.cab
    │      WinSDKInterop_amd64.msi
    │
    ├─WinSDKNetFxTools_amd64
    │      cab1.cab
    │      WinSDK_nfxtoolsm_amd64.msi
    │
    ├─WinSDKRedist
    │      cab1.cab
    │      cab2.cab
    │      cab3.cab
    │      WinSDKRedist_x86.msi
    │
    ├─WinSDKSamples_amd64
    │      cab1.cab
    │      cab2.cab
    │      cab3.cab
    │      cab4.cab
    │      cab5.cab
    │      WinSDKSamples_amd64.msi
    │
    ├─WinSDKTools_amd64
    │      cab1.cab
    │      cab2.cab
    │      WinSDKTools_amd64.msi
    │
    ├─WinSDKWin32Tools_amd64
    │      cab1.cab
    │      WinSDKWin32Tools_amd64.msi
    │
    ├─WinSDK_amd64
    │      cab1.cab
    │      WinSDK_amd64.msi
    │
    └─winsdk_intellidocs
            winsdk_intellidocs.cab
            winsdk_intellidocs.msi