http://technet.microsoft.com/en-us/library/hh831568.aspx "Features Removed or Deprecated in Windows Server "8" Beta ... The Subsystem for UNIX-based Applications (SUA) is deprecated. If you use the SUA POSIX subsystem with this release, use Hyper-V to virtualize the server. If you use the tools provided by SUA, switch to Cygwin or Mingw."