Dual Booting Windows 8.1 and Windows 10 Issues

[xMattTheRatx15]

My pc has had windows 8.1 installed on a 1TB Western Digital hdd. I recently got a 120GB Sandisk ssd plus on which I reinstalled my windows 8.1. Then I proceed to update and install Windows 10 onto the ssd. What I'm wanting to do is seamlessly switch between the two drives through my asus m5a97 bios. By default with all drives powered the pc will boot into Windows 10. If I unplug the ssd it will boot into 8.1 off the hard drive just fine. But if both are plugged in and I try to change the boot order to the hard drive first my pc goes into repair and recovery mode. I just want to be able to seamlessly switch between the two without manually unplugging my ssd. Can someone help please?

[airdeano]

when you installed each OS, you also disconnected the other drive.

if not, when slave drives are present, the OS install will write code to make

an association.

 

best to install each OS independent as per what drive is needed.

then on POST use your boot manager to select which drive/OS is needed.

 

disconnect the HDD (if installing on SSD).

boot to reinstall OS with USB boot drive.

first OS install window, press shift+F10

your should get a command window.

type>diskpart

type>list disk

type which disk is the SSD>disk X (X is the SSD) try not to select your USB drive!

type>clean

type>create partition primary align=1024

type>format quick fs=ntfs label (what your boot disk label will be)

once done, type>exit and the type>exit and continue with your install.