Registry Location For File Extension Associations

Question

Can anyone provide the exact location in the System Registry where the Default Programs for File Associations are stored? Case in point, if I would want to know the Default Programs that will open *.rtf, *.pdf, *.txt, *.doc, etc. Querying the Registry is not a problem for me. I have looked at various locations and combinations of Keys/SubKeys, but nothing specifically points to the exact location. If I change the Default Program for *.txt from Notepad.exe to Word.exe, I need to see this in the Registry. My Current Platform is Windows 10.

Answer 1

Something here may help. User settings override machine settings.

http://woshub.com/managing-default-file-associations-in-windows-10/

--please don't forget to Accept as answer if the reply is helpful--

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Regards, Dave Patrick ....
Microsoft Certified Professional
Microsoft MVP [Windows Server] Datacenter Management

Disclaimer: This posting is provided "AS IS" with no warranties or guarantees, and confers no rights.

Answer 2

Thank you DSPatrick for such a swift reply. You have actually isolated the problem for me which is:

With Windows 10 you can’t manage file association settings through the Registry

I need End Users to check for the Default Program for *.pdf on their PCs and I need to do this pro-grammatically. The only option as I see it, and as you have guided me, is to Export File Associations to an *.xlm File, then extract the Default Program associated with the .pdf Extension. This can be done by:

Dism.exe /online /Export-DefaultAppAssociations:C:\PS\DefaultAssoc.xml

This would normally not be a problem, except a new problem now arises as indicated below:

Elevated Permissions are required to run DISM.

Use an elevated commnd prompt to complete these tasks.

Unless you indicate otherwise, there appears to be no resolution to this issue.

Answer 3

Maybe you can push it via GPO

https://4sysops.com/archives/default-file-associations-in-windows-10/

Answer 4

Thanks DSPatrick, but it doesn't appear to be a viable option, at least to me. I can easily output File Associations using Dsim.exe at a Command Prompt to an *.xml file, search for the line with the .pdf extension, and see if Adobe Acrobat Reader is the Default Program (example posted below). The only problem is that I need to Run cmd.exe as Administrator in order to accomplish this.

<Association Identifier=".pdf" ProgId="AcroExch.Document.DC" ApplicationName="Adobe Acrobat Reader DC" />