VictorN:
That isn't really an option, since I want to use the already installed keyboard layouts that is available in the %windir%\system32\ directory.

But it would "solve" the problem if I distributed the dlls with the installation.

Not any other nifty solutions though?

I guess I'll have to create a kbd64.h that manage the structs for x64 bit and do a x86/x64 check on the dll-files before loading.