Does installing a language pack to Windows 10 completely change the language?

Question

On Windows 10, you basically have 2 options for installing it in a different language:

1. Install Windows 10 from the start
2. Install Windows 10 in English and then add a language pack and then set system language to that language

But does these 2 options produce different results?

I have seen computers installed using the second option fail to show text in the language pack language, but computers installed using the first option nailing it. Maybe that's because of a different reason?

Answer 1

The problem arrives when using a partially-localized language pack. When installing Windows in another language, it is always installed with a fully-localized language pack.

The difference between fully and partially localized packs is whether the pack contains 100% of all the resources necessary to localize the UI, or not. For example, some of the resources in the partially localized Danish language pack might be localized in Danish while the remaining resources are localized in English. German doesn’t have the same problem since it is a fully-localized language pack.

Some partially localized packs can use resources from another pack, installed as a base language pack, so both need to be installed. For example, ca-ES requires es-ES to also be installed.

Some areas that may particularly suffer in a partially localized pack are console applications and PowerShell Console UI, that when not localized fall back to English.