Question: I wanted to install Windows on my other hard drive with Rufus by using Windows10 ISO and without using any external USB/CD/DVD.

So I plugged in the other drive to my motherboard and I can see the drive on my PC, as well as DiskManager.

However, Rufus doesn’t show it..?

How to make Rufus show internal hard drives?

Answer: Rufus dev here. If you REALLY want to try to play with internal drives, there is a non-publicized cheat mode (Ctrl-Alt-F — be mindful that this is not the same as Alt-F) that may list internal drives, such as SATA and so on, provided they have been set as REMOVABLE by your BIOS or UEFI firmware. For instance, this cheat mode should let Rufus list properly configured eSATA drives, that you may have plugged into your motherboard.

Of course, if you use this UNSUPPORTED cheat mode, you are 100% on your own.