Certificate may not have a private key that is capable of key exchange or the process may not have access rights for the private key

When we add certificate into IIS\Server Certificates, please make sure you have given 'Read' permission for the users that's hosting your web service/site.

Start MMC and add the Certificate Snap-in, selecting the right container owner for your SSL certificate. Find the certificate (it's probably in the personal store), right click on it and choose All Tasks > Manage Private key. Grant read access to the private key to the user hosting your service.

CmdLet in windows 7

http://blogs.technet.com/b/josebda/archive/2009/11/25/download-for-powershell-v2-for-windows-7-no-need-it-s-already-there.aspx

http://blogs.msdn.com/b/saveenr/archive/2010/03/08/how-to-create-a-powershell-2-0-module-and-cmdlet-with-visual-studio-2010-screencast-included.aspx