I'm trying to help a friend fix his PC, but the supposedly simple task has turned into a mind-boggling nightmare.
Story so far: guy was fed up with his old and crowded HDD, buys a new SSD, plugs it in, creates bootable Win10 installation media, installs Windows 10 on the new drive. Everything goes well, Windows boots from the new drive just fine -- initially. So then we delete the old Windows folder from the old drive to free space. This results in the computer randomly failing to boot (but not every time). This could be resolved by manually selecting Windows Boot Manager from the boot options (which seems to be the default choice anyway but somehow isn't, apparently), at which point it would boot from the SSD every time. This seemed like a minor annoyance that was left to be resolved at a later time.
But then! Windows Update tries to perform a Windows Update, and somehow tries to do it on the now-nonexistent copy of Windows. Then it of course fails. This results in a loop of the computer restarting itself a couple of times, trying to apply the update again and failing. Then after wasting everyone's time for a while it somehow gives up and decides to boot normally from the SSD. This happens every time the computer is booted.
No problem I think. We'll just back up whatever is left on the old drive, use DISKPART to delete all partitions, then put the blank HD to use again. But no! Windows won't let me delete the system partition on the old HD. My understanding is that this means Windows still thinks it lives on that system partition and therefore won't allow it to be deleted. Why?
And how do I get around this? I guess I could unplug the haunted drive, bring it home, plug it into my computer and use my own Windows to clean it. But that's a bit troublesome in this case due to the distances involved. Is there a less laborious way?