windows 10 - How do I completely factory-reset my SSD and HDD and create a volume out of unallocated space?

I wanted to clean install Windows 10 and get rid of my current license for a few reasons (it'll expire soon anyway). I already copied all my data over to an external drive.

Then, I chose to 'Reset this PC', erasing all my personal data. I had installed Windows on my SSD, and when my PC was done resetting and booting, the installation of Windows 10 just started all by itself.

So my beginners-approach was to delete the partitions on my HDD (data only) and then of my SSD using Disk Management, hopefully including whatever made Windows install automatically.

What I actually wanted to do is to basically factory reset my drives so that I would just be given the option to install Windows 10 from the new disk I got.

Now, I have my partitions as in this picture:

If I right click on the unallocated space, I'm only given the option to create a new simple volume, but if I try to do that and make use of that space, I only get:

There is not enough space available on the disk(s) to complete this operation.

I've tried to find a solution online, but the third-party software I tried to use (EaseUS and Partition Wizard) don't seem to include what I need in their free version.

So I'm struggling with a few things at once here. If there is a way other than messing around with unallocated space and partitions to just wipe my disks and start anew - I'd be so so happy to hear it.

If there isn't (and I suppose I'll have to deal with the unallocated space first if I want to be able to use it) I'd love to know why I can't seem to create a new Volume with the unallocated space, and what I have to do with the partitions on my SSD and how to wipe it, to stop Windows from just self-installing and to be able to clean install from the new Windows 10 disk.

I can't seem to find a way to fix this problem.

Answer

Boot the windows 10 install
SHIFT F8
Should get you a command prompt

diskpart

If you are unsure of which disk is which list disk

1. select disk 0




2. clean




3. all data on disk 0 is gone

repeat for other drives as necessary

Type exit

Let windows do all the partitioning for you, on the drive you want to install windows

Partition the other drive once windows is installed.