You need to export your public key certificate and your private key into a backup file. Just backing up the public key certificate on its own is not enough for recovery.
You can export your public key certificate and your private key from a certificate’s properties dialog. You can view a certificate’s properties either in Internet Explorer (Tools->Internet Options, Content Tab then Certificates button) or from the Certificates tab in ComodoSecureEmail configuration screen by selecting the certificate and double clicking it, or by clicking the properties button.
Once you have the certificate dialog box open, click the Details tab and then click the ‘Copy to File…’ button at the bottom right.
Follow the wizard instructions and make sure you select “Yes, export the private key” on the ‘Export Private Key’ page which is the second page of the wizard.
I think your error could be that you are overlooking page two of the ‘Certificate Export Wizard’ which offers you the option to export your private key. This is the previous page to the one you are mentioning.
On page two, titled ‘Export Private Key’, of the ‘Certificate Export Wizard’ you should see two options:
‘Do you want to export the private key with the certificate?
( * ) Yes, export the private key.
( ) No, do not export the private key.’
You need to make sure you have selected, ‘Yes, export the private key.’.
A pfx or p12 file is a PKCS#12 (for more information see: http://www.rsa.com/rsalabs/node.asp?id=2138) and is used to store a private key along with a public key certificate. If you don’t export the private key they you won’t be able to export as a PKCS#12, since that’s the format for storing private keys and public key certificates together.
I’ve asked one of the team to contact you to go over this in more detail.
There should be a key export dialog page in the Microsoft Windows Certificate Export Wizard. If there isn’t for the certificate you are attempting to export, it generally means that you don’t have the private key installed for that certificate. Do the certificate properties show you have a private key installed for this certificate?
I have a question for you:
Do you have any certificate listed in the “PERSONAL” tab of the Certificates Option page of Comodo SecureEmail configuration utility?
SecureEmail shows only certificate with a private key in this tab.
Certificates in the “Other People” tab don’t have private key and just allow you to send encrypted e-mails to these people.
If you don’t have any certificate in “General” tab then you don’t have any installed Comodo certificate with a private key.
If you have any then you SHOULD be able to export it with private key.
According to your latest post - your certificates don’t have private key (when you checked certificates properties dialog), so, I think - you checked certificates in the “Other people” tab.
Also if certificate doen’t have private key - Certificate Export Wizard doesn’t show you page:
'Do you want to export the private key with the certificate?
( * ) Yes, export the private key.
( ) No, do not export the private key.’
So, We have 2 possible scenarios:
You didn’t installed certificate successfully for this user on this PC.
You’ve tried to export wrong certificates (with public keys only).
I hope this post will help, feel free to ask any questions about SecureEmail.