Hello, Mārcis_26.
Welcome to Microsoft Community.
Have you tried this method?
Open Windows Settings -> Time & Language -> Language & Region -> Add a new language (for example, English from another country) -> Check 'Set as my Windows display language' -> Install -> Wait for the installation to finish and then restart the computer to change the language -> Then remove Polish -> Then change it to the language you want.
Generally, it's not recommended to modify the registry, as arbitrary changes to the registry can cause system failures.
Disclaimer: Generally, modifying registry subkeys or work group is intended for advanced users, administrators, and IT Professionals. It can help fix some problems, however, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For further protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs.
Here is the documentation on backing up the registry.
How to back up and restore the registry in Windows - Microsoft Support
If there are any updates, please feel free to reply.
If I have any new ideas, I will respond again.
Best regards.
Malygos - MSFT | Microsoft Community Support Specialist