I'm trying to factory reset my Laptop

There are 2 different things.

1) If you want to apply the factory.wim - i.e. a factory restore.

This can be done by using external boot media - locating the factory.wim , then applying it to a partition using dism or any other program capable of applying wim files.


2) If you only want to add F8 entry.

This requires creating an entry in the BCD store. You need the path to the bootable wim file.

The bootable wim file is usually called winre.wim ( sometimes it is called boot.wim ). I am not familiar with where that would be on your system. Likely somewhere on the recovery partition - perhaps in a folder called "sources". It is a lot easier if you assign a drive letter to your recovery partition first.