Windows 10 Insider Preview I can't install this update.

Can you upload a photo or screenshot of the exact error message you're seeing. I'm not sure I understand the exact text from your first post. Thanks,
--Ed--

For whatever reason, Windows 10 sees the target drive (the driver upon which you're trying to install Windows 10) as a USB flash drive. Because we know the target is an SSD, this mis-identification needs to be fixed. How is the SSD attached to the PC? Is it plugged into a SATA port? or perhaps mSATA or M.2? According to your "My PC" info you've got an HP Pavilion PC-2026 desktop. According to the online specifications, this comes with a 1.5 TB spinner (hard disk). Is that correct? Have you added the SSD and kept the spinner, or did you replace the spinner with the SSD? You may need to get into the BIOS to make sure the SSD is being picked up properly, and occupies first place in the boot order. From the specifications page for your motherboard, I don't see an mSATA or M.2 slot (though there is a mini-card slot right near the SATA port block, so conceivably a 42 mm m.SATA might be accommodated), so I'm guessing the SSD is plugged into a SATA port (see lower right of Figures 1 and/or 2). You should plug the drive into the upper left SATA port to make sure it's in SATA0 (which should take boot order precedence).
See what you can find out in the BIOS/UEFI, and tell us more about the drive and its connection to the PC, and we can come up with more things to try to get this working for you.
HTH,
--Ed--

Here's Figure 2 from the mobo manual:

Ha! Ha! That would explain some things, wouldn't it? Glad you found a possible solution. Do keep us posted on your eventual progress and (I hope) successful installation. Thanks for the follow-up. And FWIW, I'm impressed you got a standard motherboard into an HP chassis.
--Ed--