Does KEY_WOW64_64KEY have any effect on 32 bit Windows?

Question

It appears that specifying the KEY_WOW64_64KEY flag (reference) when accessing a registry key under 32-bit Windows XP has no effect - that is, no error

Answer 1

Also, you should usually be avoiding this key - WOW64 provides a pretty complete "illusion" to 32-bit apps; just write your app properly on 32-bit without this flag, and it will still work on WOW64. Don't try to use this flag (and other mechanisms) to be "64-bit compatible".