Steve Rachui at Microsoft has put together a great PKI validation script.  The script itself validates PKI in two ways.  First, it can be used to verify third-party remote configuration certificates from the vendors supported by AMT.  Second, the script can verify that your PKI environment is properly configured to support AMT provisioning.  The script itself needs to be run from a server to work correctly.  Check out Steve’s blog to get all the details.

http://blogs.msdn.com/steverac/archive/2009/05/18/tool-to-verify-amt-certificates.aspx