Windows 10/Windows Vista Dual Boot Failing

I finally fixed my old computer, and I'm trying to dual boot it with Windows 10 Pro and Windows Vista Ultimate. I have Windows 10 installed and activated on the C drive, but I am having many issues with trying to install Windows Vista. Note that I previously had it dual-boot with Windows 10 and Windows 7, but after having many issues with using Windows 7, I formatted the drive.

Issue #1 (Resolved?): I don't have any DVD drives, and my computer can't boot from a USB, but I installed Plop Boot Manager, and that seemed to make it work.

Issue #2 (Not Resolved): Attempting to boot from USB from Plop makes the kernal say "Press any key to boot from USB." Pressing any key on my keyboard or my mouse does nothing, and Plop restarts. A method that I used to try and circumvent this was to put the files that the program Rufus put onto the USB onto the drive I wanted to install Vista on, and then boot from that drive.

Issue #3 (Resolved?): When trying to install Vista, the computer stated "Windows cannot copy the files required for installation." My method for fixing this was to boot the drive via Plop, and then there was an error saying "Windows could not update the boot configuration."

Issue #4 (Not Resolved): I tried to put the extracted ISO directly onto the drive, without Rufus, and then booted it. There is an issue where the Vista installation can't find any device drivers, and I don't know where they are.

Issue #5 (Resolved): When going into msconfig, it shows that Windows 7 is installed still, despite me having done a full format on the drive that it was installed onto.

Specs: 4gb ram, 2.5ghz intel quad, 250gb ssd for win 10, 320gb hdd for vista, asus motherboard, nvidia gt 610