Using Visual Studio, I have built an C++ application running in 32bit. It will be deployed both to 32-bit and 64-bit Windows servers. It won't be run in 64-bit mode (but rather under WoW).
Should I include both the 32-bit and 64-bit Visual C++ redistributable, and install 32bit on 32bit Windows and 64bit on 64 bit Windows, or is it enough to just install the 32bit redistributable?
Both are Microsoft products, but don't let that fool you.
Your C++ application creates a 32 bits EXE, linking to 32 bits DLLs. As it happens, one or two of those DLLs are Microsoft CRT DLLs, but the OS still uses the same rules. Therefore, you don't need the 64 bits DLLs.
The 64-bit Visual C++ redistributable package includes both 32-bit Visual C++ redistributable and 64-bit Visual C++ redistributable.