A. Goto the %windir%\SysWOW64 folder on your 64-bit installation and do a listing of all the content, including sub-directories. On a Windows Server 2008 R2 or Windows 7 full install, it's around 1GB of content. On a Server Core installation, it's about 250MB. This folder contains the Windows on Windows 64 (WoW64) files, so all of this content is required to let the 64-bit OS run 32-bit applications. A 64-bit installation is far larger than a 32-bit installation because, in addition to all its native binaries, a 64-bit install also needs many of the 32-bit binaries to run 32-bit applications.
On Windows Server Core 2008 R2, WoW64 is an optional component. I gave instructions for removing WoW64 in a previous FAQ.Related Reading:
- Q. Is Windows Server 2008 R2 built on Server 2008's kernel in the same way that Windows Server 2003 R2 was built on Server 2003's kernel?
- Top 10 New Features in Windows Server 2008 R2
- Windows Server 2008 R2: Not Your Average R2
- The Little Things About Windows Server 2008 R2
Check out hundreds more useful Q&As like this in John Savill's FAQ for Windows. Also, watch instructional videos made by John at ITTV.net.