How does Windows 2008 R2 run 32-bit applications

32bit-64bitcpu-architecturewindows-server-2008-r2

If 32-bit processor support is disabled in Windows Server 2008 R2, how does the operating system run 32-bit programs?

Best Answer

x64 CPUs can actually run 32-bit (x86) code in parallel to 64-bit code. The WOW64 layer of Windows translates the system calls of 32-bit programs to the 64-bit system routines.