P.S. I'm wondering if I need to run fdisk /mbr on the old drive in order to reset its Disk Signature (which I gather now is only the first 4 bytes of that sequence.) But I'm worried I might accidentally overwrite one of my other drives, so I think I'll try removing them and maybe booting from a recovery CD with only the old drive installed. Is there a simpler (safe) way to reset the MBR on the old drive while keeping all my current drives installed?
I realize I'm kind of talking to myself here, but I just discovered that the string of numbers I see for both drives in the Registry under HKLM\DosDevices:
44 4D 49 4F
turns up on the web a lot and so is not unique to my drives. I'm wondering it's used by Windows in the Registry to identify drives that are GPT, as are mine? Though so far I haven't found anything on the web explicitly referring to this sequence of bytes being used for that purpose.
In any case, I tried erasing the old drive by using DISKPART and running CLEAN. For the moment, Indexing Options is behaving normally again, meaning that if I add the new drive to Indexed Locations, it stays that way, whereas before I would see the old drive in its place the next time I checked Indexed Locations. Fingers crossed!
I'm still not sure how Windows was confusing them in the first place. Even though one was cloned from the other, DISKPART reported their Disk IDs as being different GUIDs. And now it seems that the DosDevice number is not used to uniquely identify GPT drives. So where exactly was the information stored that caused Windows Search to confuse them?
But if cleaning the old drive has really resolved that confusion, I guess I'm ok with not knowing!
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