Re: I'm desperate, how to install games?
I'm answering this assuming you use Windows. You need to set your system locale to Japanese.
To do that, go to Control Panel > Clock, Languages, Region > Region and Language.
From there, click the 'Administrative' tab. The button to Change System Locale should be there. Changing it will require to restart your computer.
For divided files, you extract the first file with .001.rar/zip Just click on that first file and extract it. Be sure you completed downloading all parts otherwise you'll get a corrupt file. You can use programs like 7zip or WinRAR if you don't already have a program to extract files.
Then, to install the game, you need Daemon Tools Lite (or another program that opens ISOs) to open the ISO file to install your game. Of course, everything will be in Japanese. If you've installed a lot of programs in the past, then you'll be able to guess which buttons installs the game.
Hopefully that helps you in some way...