need integration with AD?

add the AD membership provider to the web.config

<add name="ADMembershipProvider" type="System.Web.Security.ActiveDirectoryMembershipProvider, System.Web, Version=2.0.0.0,Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" connectionStringName="ADConnectionString" attributeMapUsername="sAMAccountName" />

<add name="ADConnectionString" connectionString="LDAP://server001/DC=comit,DC=local" />

change in umbracoSettings.config

  <providers>
    <users>
      <!-- if you wish to use your own membershipprovider for authenticating to the umbraco back office -->
      <!-- specify it here (remember to add it to the web.config as well) -->
      <!--<DefaultBackofficeProvider>UsersMembershipProvider</DefaultBackofficeProvider>-->
      <DefaultBackofficeProvider>ADMembershipProvider</DefaultBackofficeProvider>
    </users>
  </providers>