I have an old software that uses DirectX 9. It's quite obsolete but there are still people using it.
Win10 does not come with DX9 preinstalled and I want to add it to my installer. So far I see that there's a large (100mb) DX package from Microsoft that contains all the versions and builds of DX9 and 10. (http://www.microsoft.com/downloads/en/details.aspx?FamilyID=2da43d38-db71-4c1b-bc6a-9b6652cd92a3&displaylang=en)
Among the many version, I see, for example, "Jun2010_d3dx9_43_x86.cab" that contains the .dll, .cat and .inf. I'd say that this is sufficient for what I need so I'd add this to my program's installer (inno-setup).
I am a bit outdated on DX and DLLs knowledge. Can someone give some pointers on how to proceed and if it's right installing only one of that dll?
Thanks!
DirectX 9.0c does in fact come with Windows 10. Starting with Windows XP Service Pack 2, the "DirectX End-user Runtime" never installs DirectX on any version of Windows. The only way to update "DirectX" is to install a Service Pack, a Windows Update, or move to a new version of Windows.
See Not So Direct Setup for the full story here.
Your old application, however, likely does rely on some optional side-by-side components like D3DX9, D3DX10, D3DX11, XAudio2_7, XInput1_3, D3DCompile #43, Managed DirectX 1.1, or other thing that is only deployed by the legacy DirectX End-User Runtime. In that case, you should download the latest DXSETUP package (the April 2011 refresh of the end-of-life DirectX SDK June 2010 release on MSDN).
You can then configure a minimal package that will deploy just the DLLs you actually use. For example, if you used the D3DX9 June 2010 DirectX SDK for a 32-bit application, but that's all you needed, you can get away with an install package of just:
dxsetup.exe
dsetup32.dll
dsetup.dll
dxupdate.cab
Jun2010_d3dx9_43_x86.cab
Of course, if your application is old enough to be using a previous version of D3DX9, then you need to figure that out and use the right .cab.
See Where is the DirectX SDK? as well.