diff --git a/lib/puppet/feature/base.rb b/lib/puppet/feature/base.rb
index 1971f14f2..44a9f3fc1 100644
--- a/lib/puppet/feature/base.rb
+++ b/lib/puppet/feature/base.rb
@@ -1,33 +1,44 @@
 #  Created by Luke Kanies on 2006-04-30.
 #  Copyright (c) 2006. All rights reserved.
 
 require 'puppet/util/feature'
 
 # Add the simple features, all in one file.
 
 # We've got LDAP available.
 Puppet.features.add(:ldap, :libs => ["ldap"])
 
 # We have the Rdoc::Usage library.
 Puppet.features.add(:usage, :libs => %w{rdoc/ri/ri_paths rdoc/usage})
 
 # We have libshadow, useful for managing passwords.
 Puppet.features.add(:libshadow, :libs => ["shadow"])
 
 # We're running as root.
 Puppet.features.add(:root) { require 'puppet/util/suidmanager'; Puppet::Util::SUIDManager.root? }
 
 # We've got mongrel available
 Puppet.features.add(:mongrel, :libs => %w{rubygems mongrel puppet/network/http_server/mongrel})
 
 # We have lcs diff
 Puppet.features.add :diff, :libs => %w{diff/lcs diff/lcs/hunk}
 
 # We have augeas
 Puppet.features.add(:augeas, :libs => ["augeas"])
 
 # We have RRD available
 Puppet.features.add(:rrd, :libs => ["RRDtool"])
 
 # We have OpenSSL
 Puppet.features.add(:openssl, :libs => ["openssl"])
+
+# We can use POSIX user functions? The require returns false on Windows
+Puppet.features.add(:posix) do
+    require 'etc'
+    Etc.getpwuid(0) != nil
+end
+
+# We can use Win32 functions
+Puppet.features.add(:win32, :libs => ["sys/admin", "win32/process"])
+
+raise Puppet::Error "Cannot determine basic system flavour" unless Puppet.features.posix? or Puppet.features.win32?