[SOLVED] Windows 10 Setup won't let me select my old windows 7 install

[AoiMaiden]

Hi,
State of Decay 2 came out on steam and I wanted to play it. You have to have Win 10 to play it, so I took some space on a drive and partitioned it and began installing win 10 on it. Of course it failed, and I realized this was not going to be worth it to play one video game. So I load back into windows 7, format the partition and move on with my life. Windows 10 decided otherwise however, and decided that it now owns my bios and that I will never be able to select the operating system that I would like to use. Whenever I boot, where it should have the OS selection screen (I have 2 hard drives both with copies of win 7) it just has the windows 10 logo and a loading circle that loads for a few seconds, hits a blue screen that says something like "didnt install correctly" and then just does that over and over. How do I get back into my old windows 7? I tried installing windows 10 again but for some reason it's now saying that my partition type isn't correct, which....it didn't do the first time. I'm making a windows 7 bootable right now, and we're going to see how that goes, but is there a faster way to get this...."software" off of my computer?

 

[Alabalcho]

You can use BIOS to select which drive is bootable.
You can also use utility like EasyBCD to create ana manage boot menus.

 

[AoiMaiden]

Sorry, yea i forgot to mention that selecting the correct drive was one of the first things I checked. It was already set to my decault C drive that has my usual copy on windows 7 on it.

Other than the usb stick that isn't plugged in currently there are no windows 10 files on my computer, I formatted the partition that I was trying to install it to. There is the iso from microsoft that I made the bootable from somewhere in there but I extremely doubt my bios is mounting and booting that over the default drive.

 

[AoiMaiden]

Oh sorry, as well I got my windows 7 bootable working on my other thumb drive and tried to get that installation going on the partition I made for the windows 10, in the hopes that it would restore my select operating system screen, or that I could get into windows at all and try to remove anything windows 10 from boot up, but when it loads up it doesnt recognize the mouse or keyboard so I have no method of input for....reasons.

 

[onespeedbiker]

Windows 10 does not take control of the BIOS. Installing Windows 10 likely took control of the boot sector of the hard drive, which is why you keep seeing seeing the Windows 10 logo. If you want to get Windows 7 working again, your going to have to probably use diskpart to clean the hard drive and start from scratch. You can use either Windows 7 or Windows 10 install media to access a command prompt https://www.tenforums.com/tutorials/85819-erase-disk-using-diskpart-clean-command-windows-10-a.html