I had a devil of time trying to do this yesterday. The first time through it all seemed fine until I added the certificate to the Windows Cert store. It went in under “Other People,” not “Personal” and I couldn’t select it to sign my emails. Figuring I’d done something wrong I revoked the cert and applied again. And again. And again. Then I found a great tip that suggested I check to see if the Private Key for my cert was found. It wasn’t. So I started looking into how where my Private Key even was…

Turns out the Comodo site plain doesn’t work with Chrome. Probably the permissions are too restrictive. I tried with IE and suddenly it all made sense and it worked just fine first go.

What I really wanted was a certificate that would let me sign a PDF, I’m not really that interested in signing my mails. Sadly the template used by Comodo doesn’t seem to be set up in the idle way for document signing but it still works!