Windows 10: Non-System DIsk

I'm using a ASUS TUF505DD-AL040, and decided to upgrade my hard drive, I installed it and used a boot key to reinstall windows 10. I got a "Non-system Disk " error and it seems I can't install windows. I tried to reinstall my old hard drive who still got windows 10 on it and ended up having the same error message. Whenever I press a key, it show the default reboot and select proper boot device, and then non system disk again. I can't access BIOS and I'm starting to get really desperate, please help

:)

 

Non-system disk or disk error in Windows 10

Hi Aixa,

The Non-system disk or disk error usually occurs when the
computer is unable to find an operating system on any of the storage devices. When this happens, the computer won't be able to load your
Windows operating system. To determine what's causing this issue, we'd like to ask a few questions:

• Have you made any recent changes to your computer?
• What is the make and model of your device?
• What steps have you done so far to resolve your concern?

We're looking forward to your response.

 

Windows 7, Non System Disk?

check bios, you may have it set to boot off cd/dvd and have a disk in that drive (also could be A:\ with non system disk in too)

 

Non system disk but why ?

Thank you @Fafhrd
You are absolutely correct. I overlooked what's in Disk 0.
OK. Here's the solution:
The Boot Manager is in partition F: and that's why it's marked Active. You need to move it to C:

1. Download a free version: EasyBCD - NeoSmart Technologies
2. Install, run and follow the screen below.
   
   
   

PS. Use: Macrium Reflect Free instead as advised above