What to do with my HDD after installing OS on my SSD?

[fiddyy]

After installing a fresh version of Windows 10 onto my new Samsung 850 EVO 500gb, it booted up fine the first time when I didn't have an HDD plugged up. Then afterwards I shut down my computer, plugged in my HDD, and booted it back up and from there it wouldn't let me boot off of my SSD anymore. At first when I tried it said "A disc read error occurred. Press CTRL+ALT+DEL to restart." But after rebooting my PC and booting from the HDD a couple of times (remember that the HDD boots perfectly normal every time), it said that it was "repairing the D: drive" and it repaired but then it said in File Explorer that the D: was inaccessible and instead of showing how much storage it had it said NTFS. Now anytime I boot from my SSD it says that "No operating system was found." So did I do anything wrong when I just plugged my HDD back in after I installed my SSD's new OS? Do I need to change anything in the HDD as in get rid of certain files pertaining to the OS?
~Thank you

 

[ArtPog]

It would appear something either went awry with the fresh-install of the Win 10 OS onto the SSD or some system corruption occurred sometime following the OS install. It's really hard to tell and it's surely possible there might be something else amiss here.

I take it you passed on the possibility of cloning the HDD boot disk to your new SSD. Was that because you felt more comfortable with a fresh-install of the OS or was it because the total data contents on the HDD exceeded the disk-space capacity of your 500 GB SSD? Might that now be a consideration?

If you don't (or can't) go through the disk-cloning route I would think the only practical option at this point would be a reinstall of the OS onto the SSD. And following the install temporarily disconnect or uninstall the HDD from the system (as I believe you previously did when you first installed the OS onto the SSD). Work with the (hopefully) bootable/functional SSD for a few days if you can before re:connecting the HDD.

It would also be wise to check out the health of the SSD with Samsung's Magician program.