Installing LXLE on an Acer (with lost password) which has 22,04 already installed

Question

I installed Ubuntu22.04 on an 3 year old Acer Aspire E5-523 laptop. Unfortunately I forgot whatever password I set for the BIOS. I find 22.04 is a bit too slow for this machine so I want to try a lighter version of Ubuntu (suggestions please!) on it. Can I swap these two distros without having to use a startup disk...as I cannot get into the BIOS anymore? ....or how can I swap out GNOME for something lighter?

Answer 1

WARNING: I thought these instructions were certain to work, but they didn't actually do the trick for this user for reasons I don't understand, so proceed with caution. I personally would not recommend using these instructions again.

I don't know of a way to install one distro over the top of another without booting into the installed for the distro you want to install. However, what you could do it erase your existing OS so that you can boot from the installer.

First, make sure this is a viable solution for you. Get a screwdriver and open up the computer. Then disconnect the HDD from the motherboard, and then flip the system over without screwing anything back in just yet (unless that would result in parts falling out). Then plug in your live USB drive and try booting the system.

If the system is able to boot from the USB drive when the HDD is disconnected, you should be able to nuke the existing Ubuntu installation and then be able to boot from the USB drive to install a new distro. The easiest way to do that is to zero out the start of the main drive.

A word of warning before you proceed:

This process will destroy all data on your drive. You will lose all your operating systems, files, programs, and even your partitions and the bootloader if you do this. If you have any data you care about on any operating system on your computer, back it up before doing this, or you will lose it. ABSOLUTELY DO NOT DO THIS IF YOU ARE UNABLE TO BOOT FROM THE USB WITH THE HDD DISCONNECTED!!!

Alright, now that we're done with the scary warning, and assuming that you are able to boot from a USB drive when the HDD is disconnected, here's how to nuke the existing install.

First, make good and sure that you have a functional live USB, and that your system is able to boot from it when the HDD is disconnected.

Next, you did back up your files before thinking of doing this, right? If not, stop and back up. (Make sure to back up stuff like your Firefox saved logins and stuff, or you might lose access to your accounts if you can't remember the passwords or you used Firefox's password generator.)

Next, once the backups are made, ensure that you do not have any external drives of any sort plugged into your system. Otherwise, you could nuke the wrong drive.

Now it's time to nuke the drive. Open a terminal with Ctrl+Alt+T. Type lsblk to see the drives and partitions in your system. Each drive will have a code of some sort associated with it, with names like "sda" and the like. One of those drives will be mounted at /. This drive is your main drive (unless you partitioned your system weird at install time, but in that instance you'll probably know what drive to wipe).

Now for the scary step. Here's the nuke command:

sudo dd if=/dev/zero of=/dev/<drive ID code here>

Replace <drive ID code here> with the ID code you got from lsblk that matches your drive. You want to use the ID code that ends with a letter (e.g., "sda", not "sda1", note that your system may use a drive code other than "sda"). You will be asked for a password. Make good and sure that you really did back up everything you care about, then type your password and press Enter. Wait five or ten seconds, then press Ctrl+C. This will terminate the command before it finishes wiping the whole drive. That's fine - you only need just the start of the drive wiped.

Once that's done, reboot the system and ensure it really is wiped. The system should be unable to boot from the HDD.

Once all that chaos is finished, plug your live USB in, power the system on, and install!

(Oh, and, of course, don't forget to put the bottom cover back on your laptop.)