I imported my certificate. I then clicked on "Certificates". Then I selected "Change Certification Trust". "This is my certificate" is grayed out. I suspect that the new computer doesn't know the private key? When I try to decrypt a file it doesn't prompt for my private key, it just says "Decryption failed: No Secret Key".

Please help. I can't access my encrypted data on my new computer. "Export" appears to only export the public key. How does the new computer get the private key?