The Premium Edition of Pirform automatically exports a certificate when you close the certificate after making changes. Follow the instructions below to find these files using Windows.
 Open backup folder
By default, Pirform stores your backups under a folder called Pirform in your My Documents folder. Note that if you have changed that location then you will need to adjust these instructions accordingly.
Open My Documents and go into the Pirform folder. From there, go into the folder called Automatic Backup. So you will now be in the folder called:
My Documents\Pirform\Automatic Export
And should see something like this:
 Search for the file
Use the search feature of Windows to find the file(s) you are after. To do this, type into the search box at the top right. Typing *.pex will find all the export files, as shown below. Once you have found the file, you can import the certificate back into Pirform. Instructions on doing that are here.