Hi David, Others know more than I, but now that the Linux bootloader is in use, you should be able to add the old installation. First you need to check what software is controlling your bootup. Google will help from there. You want to add a new entry for the original disk, with the right partition info, plus paths to some bootup files and folders. Rob - Who hasn't done this for a few years. Feb. 9, 2022 1:02:45 p.m. David Baril (dpbaril [ at ] gmail [ dot ] com) <dpbaril [ at ] gmail [ dot ] com>: > On last week's Zoom call and in a subsequent post, I raised the question of updating an old (2014) Dell XPS 8700 from Linux Mint 18.3 to the latest version 20.3. I wanted to set up a dual boot environment with both versions and was having difficulty figuring out how to do so with the Legacy (MBR) BIOS. With encouragement from Jean-François and John Nash, I decided to go the route of setting up a new Mini-PC before blowing up my existing environment. > > For just under $300 on Amazon.ca, I bought a little Kamrui Mini-PC with a Celeron J4125 processor, 8GB of DDR4 RAM and a 256 GB M2 SSD - not quite as minimalist as a Raspberry Pi, but still... Again on the advice received in the call and follow-up emails, I used the Windows disk manager to shrink the size of the Windows partition and it was then a piece of cake to install Linux in the remaining space. The little machine has an expansion slot for another SSD (a standard 2.5 in), so I can do that later if I want. Now that I had a fallback option, I took another run at the old Dell... > > After a number of attempts to install Mint 20.3 on a secondary SSD on my old desktop, I kept receiving an error message that it could not install the boot loader on the new drive. I finally decided to leave it to install the boot loader on the original drive, thinking that I could set up dual booting afterwards... Wrong! The XPS 8700 machine now boots to the new drive in Mint 20.3 but I cannot boot the old 18.3 environment, although all of the data is still there on the old disk. In any case, I have pretty much managed in a couple of hours to restore my working environment (NAS mounts, applications and utilities) on the new system although I still have a hankering to wipe the system clean, update the BIOS to the latest version and convert the machine to a pure UEFI boot mode. Now that I've been through the exercise once, I know that it is not such a huge problem to configure a new install. I also have a full backup on my NAS if I need to go back and recover any more config files for apps and utilities I have yet to reinstall... > > Nonetheless, I am still curious to know if it's possible with the existing situation to get the machine to dual boot both Mint 18.3 and 20.3. Any suggestions? > > Thanks, > > > > [https://lh3.googleusercontent.com/7GnNmw13cJRYILBszPwpgk_-DPdr_s496S3ZuI_1-FtAj8lkZoSZ8-vc2w7EXA2Hxokh6ZebT39hrY59jOsmvUihzlaqK9zBBw4ir7zQVEJnl8MehxYG0JKwp6vwYle-wUWqDYg###58x55:false###]