My PC currently has one SSD containing Windows 11, a Windows Recovery partition, and a Linux Mint installation. GRUB currently manages booting. I also have a separate HDD used only for storage. I'm adding a second SSD and want to install a fresh copy of Linux Mint there, keep Windows on the original SSD, and eventually remove the old Mint partition. What order of operations is least likely to damage the EFI boot setup or leave GRUB unusable? Should I remove the old Linux partition first, or install Mint on the new SSD while both drives are connected? I'd also like to reclaim the old Linux space for Windows afterward.
3 Answers
The safest approach is to install the new system with the old SSD temporarily disconnected. Shut down, unplug the original SSD, install the new SSD, and install Mint onto it, including its own EFI system partition and bootloader. Then reconnect the original SSD and select the new drive as the primary boot device in UEFI. Once Mint is running from the new SSD, refresh GRUB so it detects Windows on the original drive. After confirming that both systems boot correctly, delete the old Mint partition and expand the Windows partition if desired. Keeping the operating systems on separate drives also means Windows updates are much less likely to interfere with the Linux bootloader, and removing Linux later is simpler.
Deleting the old Linux partition does not necessarily remove GRUB. On UEFI systems, the firmware boot entry and EFI files are usually stored in an EFI System Partition, while the rest of GRUB’s files may be under the Linux filesystem or /boot. Removing Mint can therefore leave a boot entry that points to missing files and prevent the menu from loading. Install the new Mint system first and make sure the new drive has its own EFI partition. Then configure the firmware to boot that drive and regenerate GRUB. Only after testing should you remove the old installation. You can clean up obsolete UEFI entries later with the firmware settings or a tool such as efibootmgr.
The exact result depends on your current partition and mount-point layout. Check which partition is mounted as the EFI System Partition before deleting anything; it may be shared with Windows.
You can leave both SSDs connected during installation, but be very careful. Install Mint specifically to the new SSD and verify where the installer is placing the EFI bootloader, since installers may reuse the first EFI partition they find, which could be on the old drive. Disconnecting the old SSD is more foolproof. If that is inconvenient, at least identify the new drive by its size and model, and ensure the installer creates or uses an EFI partition on that drive. After installation, boot the new Mint installation, enable Windows detection if needed, run update-grub, and test Windows and Mint before wiping the old Linux partition.
I would not resize or move the Windows Recovery partition as part of the initial installation. First get the new Linux installation and boot process working, then handle Windows partition changes separately with a current backup.
This also gives you a fallback: if anything goes wrong, the original SSD remains untouched and can still be selected directly from the firmware boot menu.