Having read this and your original post on the same subject my inclination would be to start from scratch. If you need to save any files/data do so first to an external/USB drive.

Windows.old indicates that the install that's currently operating was an upgrade from a previous version of Windows so it was not a totally clean install to begin with... probably not what you wanted anyway. When installing do NOT select "upgrade". Select the "install windows only" option.

Disconnect all drives except the one you want to install the OS onto (DVD/CD disc drive is ok to leave connected). I would also re-enable whatever you changed in the BIOS to disable IPv4 and IPv6 that you mentioned in the previous thread.

Make sure you have the latest version of Win 10 on your install media: Wouldn't hurt to re-download and put that on your install USB (or DVD) drive now. https://www.microsoft.com/en-ca/soft...load/windows10

So now boot with the install media inserted (USB drive presumably) and follow instructions.. delete ALL available/shown partitions on the drive when shown and asked after you start the process and when they are ALL deleted follow the instructions to install Win10.

Note that this process will delete all data on the drive and you will be starting from scratch with a new install of Windows 10 so do be sure there's nothing on the current install and/or drive you want to save.

There are examples of the instructions you'll see on this site...

https://www.howtogeek.com/197559/how...10-on-your-pc/