So I realise my title may be rather vague but I honestly don't know how else to word it. Essentially what happened was I was having difficulty installing Ubuntu onto my new server rig I built, so I plugged the HDD into a dock on my Win10 rig and installed Ubuntu that way. The problem is that the only way I was able to get it to work was to use a program called Unetbootin and essentially "install" the ISO for Ubuntu directly to my Win10 root directory. This allowed me to install Ubuntu onto the HDD I was using for my server rig. The issue now is that I'm stuck with a dual-boot screen every time I turn on my computer as it thinks that the ISO for Ubuntu is a separate OS and I can't get rid of it. I've gone through and deleted every file and folder that I could see that was created by Unetbootin the day that I did the install and I've also checked msconfig to make sure there wasn't a separate boot option in there (of which there wasn't). So I'm pretty much stuck. There isn't anything else I can find that references it, I've even uninstalled Unetbootin from my OS with no success in removing this secondary (if not fake) boot option. Any help would be much appreciated. This isnt a major issue for me but it does get annoying having to pick my OS every time I turn on my computer.