Windows 10: Old SSD Not Working After New Windows 10 Install

I installed Windows 10 (Version 20H2 (OS Build 19042.685) to a brand new Samsung EVO 860 SSD and everything is working OK. But when I connect my old SSD (Samsung 850) that has Windows 7 on it, that drive is not recognized by the BIOS or in Windows. It will show up in Disk Management with no drive letter as completely unallocated space. Trying to initialize in Disk Management returns an I/O error. Did the new installation cause this issue or did I mess something up switching out the drive? I have tried different SATA cables and ports and an external enclosure without success.

Computer is about 10 years old. The SSD is 5 years old, but everything was fine before the upgrade.

:)

 

New windows 10 installtion on New SSD - wont boot unless old SSD present

It seems you installed Windows while the both SSDs were connected. This would have caused your current problem. Maybe it is sufficient to do this:

1. Launch the Disk Manager.
2. Right-click drive C:, then mark it as "active".
3. Shut down Windows
4. Open the BIOS and tell it that the new SSD is the primary boot device.
5. Disconnect the old SSD.
6. Boot up normally.

If this does not work then you might have to do this:

1. Disconnect the old SSD.
2. Re-install Windows on the new SSD, using the Media Creation Tool.

 

Instal Windows 10 on a new SSD

Hi there, I've just bought a new SSD, and i would want to go for a fresh installation of Windows 10 on that device.

At the same time I need pc for work, and so i really don't want to erase my old hdd with my surely working installation, just because if i'll have problem with reinstalling drivers and so forth in the new ssd i'd want to have the possibility to take a step
back and keep going with my old installation.

I'm worried about an eventual deactivation of my working system in the case i'd have to make that step back.

Obviously is the exact same pc, i just want to take my working windows 10 installed on my old HDD as a backup.

 

Installing Windows 10 on New PC?

I'm going to be building a new PC on Christmas and want to install Windows 10 on it. I have Windows 10 on my current PC, which I installed upgrading from 8.1 with the files on a USB. How do I go about installing a clean copy of Windows 10 on this new PC? I think I recall something about installing it once makes Microsoft recognize your hardware, but since this will be a PC I'm not sure what steps I need to take. Do I need to go 8.1 -> 10 or is there a method of going directly to 10?