Since before Windows 2000, it has been against Windows Application
Development guidelines to store application specific configuration files
in the %windir% directory.  The "Common Application Data" directory was
created in Windows 95 for the storage of application specific
per-machine configuration files.  KFW continued to use the %windir%
directory for backwards compatibility with prior releases.

With the deployment of dual 32-bit / 64-bit systems, the %windir%
directory is now redirected for 32-bit processes.  64-bit and 32-bit
processes cannot open the same version of the file.  

With the release of 2003 SP1 the %windir% is also locked down to prevent
access by most user accounts.  

As a result, the krb5 profile should be moved by default to the "Common
Application Data" directory.