Unable to access windows 10 after installing windows 8.1

[Ali_Kesodia]

I have created 3 partitions first for windows 10 (already installed) second for Windows 8.1 and third one is for backup, I installed windows 8.1 along with windows 10 now i am unable to select windows 10 there is no option available for selecting operating system what to do please help?

 

[Colif]

that is the fun thing about installing an older OS on top a newer one, it can over write the MBR and cause you to have to rebuild it again..

this should be all you need: http://www.thewindowsclub.com/repair-master-boot-record-mbr-windows

 

[Ali_Kesodia]

that is the fun thing about installing an older OS on top a newer one, it can over write the MBR and cause you to have to rebuild it again..

this should be all you need: http://www.thewindowsclub.com/repair-master-boot-record-mbr-windows

After applying the fix will it allow me to choose os?

 

[Colif]

It should, it rebuilds the list of OS on PC and should create the boot menu you are after

You might want to use a win 10 installer to run the command, not sure if it makes any difference though, the win 8 one might be good enough. You can download the Windows 10 media creation tool and use it to make a win 10 installer on USB, if you don't have it already