I currently have Windows installed on one NVMe drive and just bought a second one. I want to move the existing drive to the secondary M.2 slot, install the new drive in the primary slot, and clone my Windows installation onto it. What software or method should I use, and should I swap the drives before or after cloning?
3 Answers
The physical slot usually doesn’t matter as long as the firmware can boot from the drive. Clone the installation first, shut down, install the cloned drive in the preferred slot, and test that Windows boots. If it doesn’t boot automatically, enter UEFI settings and select the new drive’s Windows Boot Manager. Once everything works, you can erase the old drive, but create a Windows installation USB first in case boot repair is needed.
You can also use a standalone NVMe cloning dock if you’d rather not clone from within the running Windows installation. Put the original drive in the source slot and the new one in the target slot, start the clone, and only swap their positions after it completes. This avoids accidentally choosing the wrong disk in the cloning software.
Install the new NVMe alongside the existing one first, then clone the old drive to the new drive while both are connected. Rescuezilla is a fairly simple graphical option based on Clonezilla, and other tools such as Macrium or the manufacturer’s migration utility can work too. Make sure the destination drive is at least as large as the used space on the source, and back up anything important before starting. After the clone finishes, shut down and swap the drives if needed, then check the UEFI boot order so the new drive starts first.

That makes sense. I’ll keep the original drive connected as the source until the clone has finished, then change the slot layout.