If you are unable to access the recovery environment by performing the 3 hard shut down method or repeatedly pressing the F8 key on startup, then you will need to create a bootable Windows 10 USB on another working PC and boot your PC from that, then rather than installing Windows 10, select ‘Repair this Computer’ that will give you access to the Recovery Environment from there
In the Recovery Environment on the USB, try each available recovery option.
Click this link: https://www.microsoft.com/software-download/windows10
to download the Media Creation Tool (Click on Download Tool Now), with that you can download the latest Windows 10 ISO (Select Create Installation Media for Another PC), you can create a bootable USB flash drive (min 8GB) using that tool Then, Boot your PC from the Installation Media you just created (change Boot Order in your BIOS)