KEY_WOW64_32KEY and KEY_WOW64_64KEY
KEY_WOW64_64KEY
on a 64-bit OS means that the registry access, no matter if it's a 32 or 64 bit process, will access the 64 bit registry view.KEY_WOW64_32KEY
on a 64-bit OS means that the registry access, no matter if it's a 32 or 64 bit process, will access the 32 bit registry view.Neither of them have any effect on a 32-bit OS.
Leaving the flag out (the default) on a 64-bit OS will send registry accesses from 32-bit processes to the 32 bit registry view, and accesses from 64-bit processes to the 64 bit registry view.
For more info, this reference page at Microsoft should tell the whole tale.
From the linked reference:
For more information, see Accessing an Alternate Registry View.
Which says:
KEY_WOW64_64KEY: Access a 64-bit key from either a 32-bit or 64-bit application.
KEY_WOW64_32KEY: Access a 32-bit key from either a 32-bit or 64-bit application.