I don't know where you got your Win 10 install media from but you can create a new one after reading -
https://www.microsoft.com/en-gb/software-download/windows10If you've been able to install Windows Repair then you must have some sort of Win 10 installed.
Boot up with the new install media, navigate to the Install screen and select Repair your computer then select Command Prompt and enter these cmds to see if they resolve.
bcdedit |find "osdevice"
For clarity that is a Pipe symbol before find and is the upper case of \
Using your partition letter instead of the X I have exampled, enter -
dism /image:X: /cleanup-image /restorehealth
sfc /scannow /offbootdir=X:\ /offwindir=X:\Windows
Enter exit to close the cmd windows, remove the install media and reboot to see if that has resolved any issues you have.
If you want to try a clean install with the new media then you may want to format your HDD first.