After re-installing Windows 7 I notice that I seem to have failed to export the private key for one of my client certificates (for Internet Explorer use).
When viewing the certificate in IE, it happily claims "You have a private key that corresponds to this certificate" but when I go into options and try to do an export it says "The associated private key cannot be found".
I still have a disk image of the hard drive of the old Windows installation, and it would be possible for me to write this image to a disk and boot up the old installation to be able to re-export the certificate (this time including the private key) but it would be really convenient if there was a way to access/extract the key and/or certificate data directly from the file system instead.
Googling indicates that the keys are stored in AppData\Roaming\Microsoft\SystemCertificates\My\Certificates\ and those files where copied from the old install to the new, but it seems the private key is not stored in those files.