Setting up NTT Hikari internet without the CD

I signed up for internet via Asahi Net and NTT West, since my apartment already had Hikari installed and Asahi Net had a bundled deal going on. I've received the modem, the cable to the Hikari box, and what looks like a LAN cable, and all the wires are in the right place (I think), but the set-up CD doesn't run on my computer because it's not Japanese (Windows 10), and I have no idea where to enter the ID and password NTT gave me. I know very little about wireless (I didn't know the difference between modem and router), and the language barrier isn't helping.

I plugged the LAN cable that came with the modem into the wireless router my apartment's predecessor left behind for me, and on her advice I entered the router's password when it popped up on my wireless list. I now somehow have limited internet: sites like YouTube, Facebook, and Netflix will work, as well as Yahoo and Google's search pages, but I can't open any other site.

NTT's website told me to start a PPPoE (whatever that is?), but when I tried it on wireless, it told me there was a problem with the modem.

I then unplugged the LAN cable from my router and put it directly in my laptop, and I managed to read enough Japanese to download a setup file from NTT's website, but it wouldn't run on my computer either. The internet works exactly the same with the LAN plugged into my computer, but the connection that comes up still has the name of the wireless router on it, not NTT's modem.

Did I mess up by using the router first? Does anyone know how to find the place I need to enter my ID and password without the setup CD, because I feel like I shouldn't have any internet without doing that first? I have an ID and password from Asahi Net, too; should I be using that in some way? Or try to contact them? The timing of my job makes it hard to call NTT's English line, and the few times I have I end up on hold forever. They also don't take emails.

I advise you that you connect your computer with wired connection at first.
I expect that you have a Lan cable connector on the wall of your room.
1. Lan cable connector (on the wall) - wired connection - your computer: input your Asahi net password to your COMPUTER. when it works, everything is fine.
2. Lan cable connector - wired connection - router (when NTT gives you) - wired connection - your computer : you need to communicate to the router. input your Asahi net passpord to your ROUTER.
3.when everything going well : confirm that wireless function of the ROUTER is "on". unplug wired connection between the router and your computer. you connect your computer and the router through wireless with that you input ROUTER password to your computer. you can connect your smartphone to ROUTER with inputting ROUTER password to SMARTPHONE.

try this video

https://www.youtube.com/watch?v=vNHJsPgIrTs

Have all your credentials with you for the setup