Question

 <system.serviceModel>
    <services>
      <service
          name="myClass.IService1"  behaviorConfiguration="myService">
        <endpoint
          name="ep1"
          address="http://localhost:57582/Service1.svc"
          contract="IService1"
          binding="basicHttpBinding"
          />
        <endpoint 
             address="mex"
             binding="mexHttpBinding"
             contract="IMetadataExchange" />
      </service>
    </services>

    <behaviors>
      <serviceBehaviors>
        <behavior name="myService">
          <serviceMetadata httpGetEnabled="true" />
          <serviceDebug includeExceptionDetailInFaults="false" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
  </system.serviceModel>

but still i am getting the following error::
Failed to add a service. Service metadata may not be accessible. Make sure your service is running and exposing metadata.

Answer 1

1. your service name IService1 – this looks like it might in fact be
   the contract. If you are using the normal templates then remove the
   I from IService1

2. If you are IIS hosting you can remove the address as the location of the .svc file is automatically the address.

3. The contract needs to be fully qualified including the namespace of the contract interface

with this in place your metadata should be served from <.svc file location>?wsdl