Windows Changed my PFX certificate - Old certificate will not import

Jorg Smash 1 Reputation point

Windows 10 Pro
Version 2004
Build 19041.928

Hey guys. This is the second time my Windows machine has decided to change my PFX certificate on me without asking/warning. I have an external HDD with files that are encrypted with a PFX file that I created in 2018. About 6 months or so ago, I couldn't access any of my files. Digging into the issue, Windows had switched my PFX certificate to a new one that I never generated. I guess the system generated it on its own. I was able to restore my old PFX certificate and access the files again. (Thank you backups!!!)

Fast forward to today. It has happened again. My Windows system has switched to a new PFX file that was generated last month. I still have my old PFX certificate, but now I am getting an error when trying to import it. I can no longer access my encrypted files.

Here are some screenshots of my issues:


Windows Server Security
Windows Server Security
Windows Server: A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.Security: The precautions taken to guard against crime, attack, sabotage, espionage, or another threat.
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  1. Daisy Zhou 19,276 Reputation points Microsoft Vendor

    Hello @Jorg Smash ,

    Thank you for posting here.

    To better understand your question, please confirm the following information at your convenience.
    1.Is the issuer "Leona" your internal Windows CA server?

    2.Are your certificates (old cert and new cert) all self-signed certificates? If so, how did you generate old cert?

    Tip: Self-signed certificate means Leona issues cert to Leona.

    3.Does the issue occur on the same client or difference clients?

    4.Please confirm to whom are the new and old certificates issued?

    For example:

    5.Based on "Fast forward to today. It has happened again. My Windows system has switched to a new PFX file that was generated last month.", where is this new certificate installed when you find it (Machine store or User store or other location)?

    6.What account did you use to log on this Windows client? Leona or other account?

    7.Could you import this new certificate into User store as below?

    Should you have any question or concern, please feel free to let us know.

    Best Regards,
    Daisy Zhou


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