diff --git a/lib/puppet/provider/group/windows_adsi.rb b/lib/puppet/provider/group/windows_adsi.rb
new file mode 100644
index 000000000..4468d0071
--- /dev/null
+++ b/lib/puppet/provider/group/windows_adsi.rb
@@ -0,0 +1,48 @@
+require 'puppet/util/adsi'
+
+Puppet::Type.type(:group).provide :windows_adsi do
+  desc "Group management for Windows"
+
+  defaultfor :operatingsystem => :windows
+  confine :operatingsystem => :windows
+  confine :feature => :microsoft_windows
+
+  has_features :manages_members
+
+  def group
+    @group ||= Puppet::Util::ADSI::Group.new(@resource[:name])
+  end
+
+  def members
+    group.members
+  end
+
+  def members=(members)
+    group.set_members(members)
+  end
+
+  def create
+    @group = Puppet::Util::ADSI::Group.create(@resource[:name])
+    self.members = @resource[:members]
+  end
+
+  def exists?
+    Puppet::Util::ADSI::Group.exists?(@resource[:name])
+  end
+
+  def delete
+    Puppet::Util::ADSI::Group.delete(@resource[:name])
+  end
+
+  def gid
+    nil
+  end
+
+  def gid=(value)
+    warning "No support for managing property gid of group #{@resource[:name]} on Windows"
+  end
+
+  def self.instances
+    Puppet::Util::ADSI::Group.map { |g| new(:ensure => :present, :name => g.name) }
+  end
+end
diff --git a/spec/unit/provider/group/windows_adsi_spec.rb b/spec/unit/provider/group/windows_adsi_spec.rb
new file mode 100644
index 000000000..7faaa1a8c
--- /dev/null
+++ b/spec/unit/provider/group/windows_adsi_spec.rb
@@ -0,0 +1,79 @@
+#!/usr/bin/env ruby
+
+require 'spec_helper'
+
+describe Puppet::Type.type(:group).provider(:windows_adsi) do
+  let(:resource) do
+    Puppet::Type.type(:group).new(
+      :title => 'testers',
+      :provider => :windows_adsi
+    )
+  end
+
+  let(:provider) { resource.provider }
+
+  let(:connection) { stub 'connection' }
+
+  before :each do
+    Puppet::Util::ADSI.stubs(:computer_name).returns('testcomputername')
+    Puppet::Util::ADSI.stubs(:connect).returns connection
+  end
+
+  describe ".instances" do
+    it "should enumerate all groups" do
+      names = ['group1', 'group2', 'group3']
+      stub_groups = names.map{|n| stub(:name => n)}
+
+      connection.stubs(:execquery).with("select * from win32_group").returns stub_groups
+
+      described_class.instances.map(&:name).should =~ names
+    end
+  end
+
+  describe "when managing members" do
+    it "should be able to provide a list of members" do
+      provider.group.stubs(:members).returns ['user1', 'user2', 'user3']
+
+      provider.members.should =~ ['user1', 'user2', 'user3']
+    end
+
+    it "should be able to set group members" do
+      provider.group.stubs(:members).returns ['user1', 'user2']
+
+      provider.group.expects(:remove_members).with('user1')
+      provider.group.expects(:add_members).with('user3')
+
+      provider.members = ['user2', 'user3']
+    end
+  end
+
+  it "should be able to create a group" do
+    resource[:members] = ['user1', 'user2']
+
+    group = stub 'group'
+    Puppet::Util::ADSI::Group.expects(:create).with('testers').returns group
+
+    group.expects(:set_members).with(['user1', 'user2'])
+
+    provider.create
+  end
+
+  it "should be able to test whether a group exists" do
+    Puppet::Util::ADSI.stubs(:connect).returns stub('connection')
+    provider.should be_exists
+
+    Puppet::Util::ADSI.stubs(:connect).returns nil
+    provider.should_not be_exists
+  end
+
+  it "should be able to delete a group" do
+    connection.expects(:Delete).with('group', 'testers')
+
+    provider.delete
+  end
+
+  it "should warn when trying to manage the gid property" do
+    provider.expects(:warning).with { |msg| msg =~ /No support for managing property gid/ }
+    provider.send(:gid=, 500)
+  end
+end