hi it happens when your  keyboard isnt set to japanese language.
Download and install jp language and change your keyboard.
I am using windows 10 and it is working for me

I even changed the computer's locale to Japanese and got Nuno's same problem before and after the change! I know this isn't better then BK2 and BK3 but just thought of trying BK1 out to see how similar to the other BKs it is

as long as you have app locale, you don't have to set the locale system to japanese. just add japanese keyboard (and make it U.S. if you don't plan to use the letters), grab nvda and instant translate, install both then set up the hotkey. everything should be working fine

We sure have instant translate, else we couldn't play BK2 and 3! But I'm understanding Nuno's problem about  the game because I'm having it too. The strange thing is when I add the Japanese keyboard, BK3 stops connecting to the server, and BK1's problem still persists, so I prefer having one trouble instead of two! ! The problem is that I get an error whenever launching BK1. Nothing, even the intro, worked since the game needs a certain component which, just I don't know!
The Japanese keyboard will make me have 4 keyboards and will make me lose myself when doing my work as a translator

The Bk1 installer (at least the one I have, 1.12) is missing some files it needs to run.
Create a folder in bk1 named data, and copy these files from bk3's data into it:
ScreenReaderApi.dll, nvdaControllerClient.dll, dolapi.dll and SAAPI32.dll.

If you're using NVDA and get stuck at the player name screen, press NVDA+f2 then enter. I have an add-on to fix this which I wrote for the text games which have the same issue.

weird, these problems don't happen to me at all even though i miss those files