Certificate

Hi,

       I follow this link
       http://technet.microsoft.com/en-us/library/hh831348.aspx
       to make a 2-tier pki server.
       pc1=DC1, pc2=CA, pc3=APP1, pc4=MAIL, pc5=LYNC (not installed yet)

      and it works fine, or I thing it works fine!

      Now I install Exchange 2013
      and now created a request for certificate.
      save it to \\mail\cert-req\test.REQ
      start my offline CA, then go to Certificate Authentication, ad issue the test.REQ, then retrieve it as test.crt.
      save it to \\mail\cert-req\
      then open it up click detail, copy to file, select BASE64 and save it as test.cer.
      When back into exchange 2013 web admin, certificates, click on complete then type \\mail\cert-req\test.cer, it completed but show Invalid.

      How can I use my PKI to validate my exchange 2013 ?

      How can I make my PKI validate certificates so that exchange and other software can use them and valid.

       Thanks.