External Hard Drives cause temporary display shutdown during startup

I would also do:
- Copy all disk Y: (disk 6) to another drive.
- Open disk management and delete ALL disk 6 partitions, then create new and format as NTFS.
- Rename the drive letter back to Y:
- Copy data back to Y:

Thanks, Jack. That EFI partition is not on the system drive. It's on a 2TGlyph external drive. I assume I can delete it from the external drive, yes.?

I've been dodging getting a new machine for several years. I'm in the middle of a project under contract and deadline. But your list made me think I should just bite the bullet, get a new rig, take a few days and migrate my applications from Windows 7 to Windows 10.

And thanks M7. Will do as you suggest.

The bad news are that new computers only come with Win 10.
Your hardware is good.
My sugestion:
- Backup your data on another disk.
- Disconnect all other disks, leaving only the Dell OS drive.
- Do a factory recover (it will format the drive and install the OS from an image on the Recover partition)
- Install the updates - MS releases SP2 for Windows 7 - Windows 7 Help Forums
- Reinstall all programs.
- Recover your data from the backup.