This question already has an answer here:

Due to injuries, I have been unable to use my computer since early 2015. As a result, I have 14.10 on my system. I'm getting "Failed to download Repository Information". I've tried the solutions listed in 141512 with no joy. How can I bring my installation current without dump / restore?

marked as duplicate by karel, N0rbert, Fabby, Eric Carvalho, Zanna May 2 '18 at 20:26

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • 4
    Possible duplicate of Can I skip over releases when upgrading? and Reinstall Ubuntu keeping data There are too many releases between 14.10 and 18.04 to skip over them, so you should reinstall the OS instead of upgrading it. – karel Apr 30 '18 at 21:58
  • Did you set up your install to have /home on a separate partition? If so, just do a "something else" install, formatting only /. If no, you are faced with a choice: which is easier for you - back up your data and reinstall, or move your /home to its own partition, then do the "something else" install. – Organic Marble Apr 30 '18 at 22:00
  • When running the solutions, did the errors change at all? Can you add text from the failed upgrade to your question? Last year I upgraded a version 13.10 to 16.04LTS. I had initial errors but was able to work out the errors and have a stable upgrade that never experienced a glitch. Starting over with a reinstall always work. But you could also start out with working out the errors experienced in the upgrade process. – L. D. James Apr 30 '18 at 22:59
  • 2
    Have you tried running sudo do-release-upgrade? :) – Ads20000 Apr 30 '18 at 23:06
  • I get: Checking for a new Ubuntu release Your Ubuntu release is not supported anymore. For upgrade information, please visit: ubuntu.com/releaseendoflife Err Upgrade tool signature 404 Not Found [IP: 80] Err Upgrade tool 404 Not Found [IP: 80] Fetched 0 B in 0s (0 B/s) – James Norman May 2 '18 at 18:48

Browse other questions tagged or ask your own question.