<system.web>
    <authentication mode="Windows">
        <identity impersonate="true"
            userName="Administrator"
            password="LALLA$26526"/>
     </authentication>
</system.web>

Parser Error Message: Unrecognized element 'identity'.

Line 50:    <system.web>
Line 51:        <authentication mode="Windows">
Line 52:            <identity impersonate="true"
Line 53:                 userName="Administrator"
Line 54:                 password="LALLA$26526"/>

<system.web>
  <authentication mode="Windows"/>
  <identity impersonate="true" userName="foo" password="bar"/>
</system.web>