Failure Installation Exchange 2013 SP1

Step 7 of 14

Mailbox service:TransportRule

Error:
The following error was generated when "$error.Clear();
          Install-ExchangeCertificate -services IIS -DomainController $RoleDomainController
          if ($RoleIsDatacenter -ne $true -And $RoleIsPartnerHosted -ne $true)
          {
            Install-AuthCertificate -DomainController $RoleDomainController
          }
        " was run: "An IIS directory entry couldn't be created. The error message is The system cannot find the path specified.
. HResult = -2147024893".