Wow64 (Win32 emulation on 64-bit Windows) refers to the software that permits the execution of 32-bit x86 applications on 64-bit Windows. It is implemented as a set of user-mode DLLs, with some support from the kernel for creating 32-bit versions of what would normally only be 64-bit data structures, such as the process environment block (PEB) and thread environment block (TEB). Changing Wow64 contexts through Get/SetThreadContext is also implemented by the kernel. Here are the user-mode DLLs responsible for Wow64:
Wow64.dll. Manages process and thread creation, and hooks exception-dispatching and base system calls exported by Ntoskrnl.exe. It also implements file-system redirection and registry redirection.
Wow64Cpu.dll. Manages the 32-bit ...