I recently returned to my Kubuntu computer after being away for a very long time and completely forgot the login password. I thought I had saved it somewhere, but apparently I didn't. Is there a way to regain access or reset the password without wiping the drive and installing everything again? I'll definitely store the new password securely afterward.
3 Answers
Another recovery option is to mount the installed root partition from a live environment, generate a new password hash, and replace the old entry in `/etc/shadow`. That avoids a full reinstall, but it’s easier to make a mistake than using `chroot` and `passwd`, so I’d only use it if the normal password-reset method doesn’t work. Full-disk encryption changes the situation completely: you must still know the encryption passphrase to access the files.
It’s usually fixable without reinstalling, unless the root partition is fully encrypted and you’ve also forgotten the encryption passphrase. The most reliable approach is to boot from a Kubuntu or other Linux live USB, mount the installed system, enter it with `chroot`, and run `passwd USERNAME` to set a new password. You’ll need to identify the correct root partition and mount any necessary system filesystems first. If you’ve forgotten the username, the `users` command or the account directories under `/home` can help identify it.
You may also be able to reset it from the bootloader by editing the Linux boot entry and adding `init=/bin/bash`, then remounting the root filesystem as read-write and running `passwd USERNAME`. However, recovery behavior varies, and on Ubuntu-based systems the root account is often locked, so single-user mode may still ask for credentials or fail to provide a usable root shell. A live USB is generally the safer and more consistent option.
That’s the important distinction: single-user mode isn’t guaranteed to provide password-free root access on every Debian-based installation. If the root account is locked, booting a live environment and using `chroot` is usually the dependable fallback.