"backed up" EFS files' User is on a dead computer, how can I access those files?

Question

"backed up" EFS files' User is on a dead computer, how can I access those files?

JT M 0

For years, I have been copying important files from Win10 off to a USB drive formatted in exFAT. Once in a while, I checked that I could open some of the copied files and it all seemed to work fine.

The computer I used perished. I bought a new one and initialized the Windows 11 Home environment.

When I try to access the "backup" files on the USB drive, I cannot open any of them! They are all set to be accessible only by my account on my now-dead computer!!

Apparently, the files were encrypted using "Microsoft Enhanced Cryptographic Provider v1.0". I recovered the certificates for the user-account from my old hard drive and imported them into the new computer using certmgr.msc. But I continue to be unable to open (or even to copy/paste!) the files.

The error reported by Edge when I try to open a PDF file is:

The file at **file:///D:/UserFiles/Taxes/TurboTax/DL/TDAmeritrade.pdf** is not readable. It may have been moved or removed, or file permissions may be blocking access.
ERR_ACCESS_DENIED

When I right-click that file and select Properties, there is no Security Tab. From Properties, I can click Advanced->Details to see a list of "Users who can access this file". The only User in the list is my account from the old computer. This is the dialog that appears when I click "Add...":

5995070

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Answer 1

Carl-L 21,320 Microsoft External Staff Moderator

Hello, JT M

Welcome to Microsoft Q&A forum.

This seems unusual for a normal exFAT drive. Before we proceed, may I have a photo of the full error message to check for you? Please remember to remove all personal information before posting?

I'm waiting for your reply.

JT M 0 Reputation points

2026-09-05T18:47:54.3366667+00:00

Hi Carl! I appreciate your interest in my problem.

Your observation appears to be correct, my issue is not really related to the use of exFAT. I have added a "FOLLOWUP" section to my original post explaining that I have learned that the files were encrypted while being stored.

I welcome your insights into how to proceed.
JT M 0 Reputation points

2026-09-06T22:41:41.04+00:00

Carl, I have revised the original question to reflect my progress and current circumstances. I hope you will have a look and offer guidance because I am stuck!
Carl-L 21,320 Reputation points Microsoft External Staff Moderator

2026-09-09T13:23:29.91+00:00

Hello, JT M

Thanks for replying.

I'll see what I can do. I'll keep you updated.
Carl-L 21,320 Reputation points Microsoft External Staff Moderator

2026-09-10T13:35:19.6+00:00

Hello, JT M

Thanks for your patience.

Can you please open an elevated command prompt and run cipher /c "D:\UserFiles\Taxes\TurboTax\DL\TDAmeritrade.pdf"? When you got the output, please compare it with the thumbprint on the file properties. Then please run certutil -user -store My to find the EFS certificate in the personal store and check if Private key is present.

I'm waiting for your reply.
JT M 0 Reputation points

2026-09-10T16:06:23.71+00:00

Hi Carl.

The thumbprints match between the file's properties and the output from cipher.

The output from certutil includes a certificate whose Cert Hash(sha1) matches the thumbprints. This certificate has no mention of "Private key"; it includes text "Missing stored keyset".

Thank you for helping. I'm eager to make progress on this!