Here is how to recreate the private key for an installed certificate.
- Open the Certificates management console (Start > Run > MMC > Add/Remove Snap-in > Certificates > Computer Account > Local Computer)
- Expand Certificates (Local Computer) > Personal > Certificates
- View the properties of the certificate you want to create a private key for. On the Details tab, click Serial number.
certutil -repairstore my "<Serial Number>"