Windows 8.1 will not boot after installing Linux 10 CD HD2

[Buffki]

I installed a linux CD on a second harddrive. Now 8.1 will not boot. I can log in but then the screen flashes loads icons, flashes.

It is unusable. Help please.

Safe mode works

 

[broe23]

It is because Grub is the main Boot Loader. If you want both to run, you will need to see the following instructions. How to Configure the GRUB2 Boot Loader Also see Set Windows as Default OS when Dual Booting Ubuntu