1. When you use the expression "clear (my) hard drive", what exactly does that mean? Are you referring to deleting all the programs you installed on the PC, and including your personal data, photos, audio-visual material, etc.; what?
2. So all you want remaining on the drive is your Win 8.1 OS so that you can boot to that OS? Is that it?
3. Assuming the above is correct, what is the purpose of this exercise? Is it that all you're interested in is starting with a "clean slate", so to speak, with only the OS installed so that the drive is bootable? Is that what this is all about?
4. You can install Win 8.1 using Microsoft's Media Creation Tool - see...
You will need your OS's product key...if you don't know it see...
for their ProduKey which we've found to be a reliable product for displaying the ProductID.