O'Reilly logo

Microsoft® Windows® Internals: Microsoft Windows Server™ 2003, Windows XP, and Windows 2000, 4th Edition by David A. Solomon, Mark E. Russinovich

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Wow64

Wow64 (Win32 emulation on 64-bit Windows) refers to the software that permit the execution of 32-bit x86 applications on 64-bit Windows. It is implemented as a set of user-mode Dlls:

  • Wow64.dll: Manages process and thread creation, hooks exception dispatching and base system calls exported by Ntoskrnl.exe. It also implements file system redirection and registry redirection and reflection.

  • Wow64Cpu.dll: Manages the 32-bit CPU context of each running thread inside Wow64, and provides processor architecture-specific support for switching CPU mode from 32bit to 64-bit and vice versa.

  • Wow64Win.dll: Intercepts the GUI system calls exported by Win32k.sys.

The relationship of these Dlls is shown in Figure 3-31.

Figure 3-31. Wow64 architecture

Wow64 Process ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required