AIR certificate problem

I can't install published packages of AIR apps for desktop.  I did it a few times, but then in the next session, it had me do a new certificate, or I didn't know how to use the old one, so I made a new one (this is the electronic signature thing where I put in the developer name and a password and my country etc.) and now when I publish (which works fine) and then try to open to install the package, I get an error saying that the certificate doesn't match what is in the published app.  My first certificate has since been copied over by the new one, so I can't get it back.  It's not even in my recycle bin on my Windows 10 OS.  So, I think I need to clear all connections between AIR and the old certificate or something.  Can anyone point me in the right direction?