SignTool Remove

Question

Hello,

Why SignTool can sign many file types but "Remove" is not added to most of them?!

I signed some .msix files, need to revert:

SignTool Remove /S /Q "D:*.msix"

SignTool Remove /S /Q "D:\Setup.msix"

SignTool Error: Unsupported file type!

Where to request feature to be added to Windows SDK?

Do you think it's possible to add or trying is a waste of time?

Thanks.

Answer 1

Hi @Halifax Crosby ,

Thanks for reaching out.

SignTool is great for adding digital signatures to lots of file types, but removing them isn’t supported across the board - .msix files fall into the “unsupported for removal” category. The reason is mostly about how .msix packages are built: unlike .exe or .dll files where the signature is easy to peel off, .msix packages are designed to be secure and tamper-resistant. Signatures in .msix aren’t just surface stickers - they’re baked into the package in a way that SignTool doesn’t currently know how to safely remove. That’s why you’re seeing the “Unsupported file type” error.

If you want this functionality added, the best way is to submit a feature request through Microsoft’s Feedback Hub, which is built into Windows. Here’s how to do it:

1. Press Win + F to open the Feedback Hub.
2. Give your request a clear title.
3. In the description, include:
   • The fact that you can sign .msix files but can’t remove signatures.
   • Why removing a signature would help (testing, deployment corrections, or development workflows).
   • Example commands that currently fail, like SignTool Remove /S /Q "D:\Setup.msix".
4. Optionally attach screenshots or examples if you have them, they make the request easier to understand.
5. Submit the request and, if you find similar requests, consider upvoting them to increase visibility.

While there’s no guarantee it’ll be implemented immediately - because security for .msix is a high priority - Microsoft tracks developer feedback carefully, and requests with clear scenarios and impact sometimes make it into future SDK updates.

As a temporary workaround, if your goal is just to “undo” a signed .msix, another approach is to rebuild the package unsigned or sign a fresh copy rather than trying to remove the signature from an existing file.

Hope this helps! If my answer was helpful - kindly follow the instructions here so others with the same problem can benefit as well.