You're welcome.
The weird thing that happened for me is that when I originally downloaded the Fuwanovel torrent, I would try to mount the togainu.img file, but I would get an error message saying the image was corrupted. Even changing it to an .iso didn't work. So then I installed Virtual Clone Drive, which can mount .ccd files like the one in the torrent. Once I installed that, I right clicked the togainu.ccd file, and mounted it. That got everything working for me, and I was finally able to install the (virtual) disc. So if your friend can't even mount the disc, then I would start with that.
If she's gotten that far, but then gets an "administrator" error message when trying to load the installer, even when she's logged in as administrator, then you have to go and download an updated version of the game (togainunochi.exe), which I found on the aarinfantasy forum:http://aarinfantasy.com/forum/f49/t188768-togainu-no-chi-administrator.html