Thursday, February 10, 2011

Windows 64Bit OS - Directory Layout

Short and sweet, as I had someone ask me about this today...

The \windows\system32\ directory on 64 bit version of  Windows does not contain 32 bit files it contains 64 bit files.    The 32 bit files are stored in \windows\SysWOW64

WOW stands for "Windows on Windows"

Go figure, the 32 bit files are in a directory with 64 in it, and the 64 bit files are in a directory with 32 in it.

According to the road map the next version of Delphi should be able to produce 64bit applications so it's important to know this detail.


  1. ...and the 64-bit ODBC-Administrator is called odbcad32.exe

  2. The other point that people should realize is that their HKEY_LOCAL_MACHINE\Software keys, read or written to from a 32 bit Delphi apps registry keys are being redirected to the Wow6432Node, in the actual physical system registry. So if you run the 64-bit regedit.exe and look for your app's keys, remember to go to the Wow6432Node and look there.

    For example, Delphi's own IDE settings are at HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Embarcadero\BDS\8.0 instead of at HKEY_LOCAL_MACHINE\SOFTWARE\Embarcadero\BDS\8.0