Ok so I see many people that get this error so I decided to post a thread so no more people ask about this.
So if you get this error
fatal error C1083: Cannot open include file: 'd3d8.h': No such file or directory
The thing you need to do solve this error is to install Download details: DirectX 9.0 SDK Update - (Summer 2004)
After you installed this, if you have Microsoft Visual C++ 6 you need to do the following things : Tools > Options > Tab "Directories"
Then you need to clilc the suspension point "..." and find the place where you intsalled your SDK and include it in your project. You need to inlcude the "Includes File" and the "Library Files"
Library Files should be situated
C:\PROGRAM FILES\MICROSOFT DIRECTX 9.0 SDK (SUMMER 2004)\LIB
and Includes Files
C:\PROGRAM FILES\MICROSOFT DIRECTX 9.0 SDK (SUMMER 2004)\INCLUDE