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I deleted my Ubuntu partition from my Windows 10 drive, but now when I power on the PC, Windows does not start. All I see is "error: unknown filesystem. Entering rescue mode... grub rescue>_", so I thought to change the boot order. However, I can't enter the BIOS screen. Before, I was able to change the boot order by pressing F12, but now if I press it, it does nothing. I can't even enter into the bios with F2 when it says "press F2 to enter bios" and "F12 boot options". I can't see those options anymore.
What could be causing this?