msix Registry.dat usage

Question

Hello

My desktop Framework WinForms packaged app has a Registry.dat to have some preloaded entries.

However, adding these keys to my Registry.dat which only packaged app has access to it, will have any effect?

Thanks.

HKLM\SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION

HKLM\MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem :: LongPathsEnabled

HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.3\Client :: Enabled / DisabledByDefault

HKLM\SOFTWARE\Microsoft.NETFramework\v4.0.30319 :: SchUseStrongCrypto / SystemDefaultTlsVersions

Answer 1

Hi @Halifax Crosby ,

Thanks for reaching out.

The Registry.dat file inside an MSIX package is private to your app - Microsoft Learn: Registry in MSIX. It acts like a private notebook for your app. Windows does not automatically apply these settings to the system registry, and the app can read from Registry.dat but cannot modify it.

So, adding keys like:

• FEATURE_BROWSER_EMULATION (Internet Explorer behavior)
• LongPathsEnabled (file system paths)
• TLS 1.3 client settings
• .NET Framework encryption settings

to your Registry.dat will not affect Windows globally. They are only visible inside your packaged app.

If you need these settings to apply system-wide, your app must write to the actual HKLM registry, which usually requires administrator permissions.

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