Cloned SSD Won't Boot When Original Drive Is Also Connected??

guduka

Okay so I cloned my old 500GB SATA SSD to a new 1TB NVMe using Macrium Reflect Free. Clone said "successful," I set the NVMe as boot priority #1 in BIOS, disconnected the old SATA SSD, and Windows boots perfectly. Boots in like 15 seconds, everything works. Great.

Then I reconnected the old SATA SSD because I wanted to use it as extra storage. Changed BIOS boot priority so NVMe is still #1. But now Windows just hangs at the motherboard splash screen forever. Like, 10+ minutes and nothing.

Unplug the SATA SSD = boots fine again. Plug it back in = hangs. Every single time.

Both drives show up in BIOS. Boot priority is correct. I don't get it. The old drive isn't even set to boot, why is it breaking everything just by being connected??

Running Windows 11 23H2, ASUS B550 motherboard if that matters.

kiist_ly0

Classic disk signature collision. When you clone a drive, the cloning software copies literally everything including the 4-byte disk signature (MBR) or the 16-byte disk GUID (GPT). Windows uses this identifier to know which disk is which. When both drives report the same ID, the boot manager gets confused.

Easy fix. Boot with only the NVMe connected, then run this in admin Command Prompt:

diskpart

list disk

select disk X (your NVMe - verify by size)

uniqueid disk id=12345678

Replace 12345678 with a random 8-digit hex value. That gives the NVMe a new unique ID so Windows can tell them apart.

Then reboot with both drives connected and see if it works.